taxonID	type	description	language	source
03B087E55B74FF81FF79F47CFB41FD5A.taxon	description	The speciose, cosmopolitan genus Hydraena is well-defined by the following autapomorphic characteristics: 1) presence of a labral-mandibular interlocking device (Perkins 1989); 2) mentum with an acute median projection anteriorly (Perkins 1989); 3) various complex sensilla (Perkins 1997); and 4) specialized features of the exocrine secretion delivery system (Perkins 1997). There is general agreement among current workers that Hydraena is monophyletic, based on these characters (for example, Jäch, et al. 2000). The PNG species meet these generic criteria. The division of Hydraena into subgenera is currently a matter of uncertainty. Some groupings of species into large putative monophyletic groups is more certain, but the sister group relationships of these groups are less clear, and presently under study (Ignacio Ribera and colleagues, for example, are currently doing DNA analysis). The morphological cladistic analysis of Jäch, et al. (2000) concluded that " the great phylogenetic alternative " to Hydraena (s. str.) had been found in Hydraena (Hydraenopsis). The PNG species of Hydraena are most probably related to species placed by Jäch, et al. in Hydraena (Hydraenopsis). However, I prefer not to formally assign species to subgenera until the results of a comprehensive DNA analysis are published and it is shown that Hydraenopsis is not nested within what is now considered Hydraena (s. str.).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	description	(Figs. 10, 12, 388, 431)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	materials_examined	Type material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (NHM). Paratypes (276): Eastern Highlands Province: Akameku-Brahmin, Bismarck Range, 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (1 ZSM); Marawaka, Ande, 1700 m, 7 ° 1.697 ' S, 145 ° 49.807 ' E, 8 xi 2006, Balke & Kinibel (PNG 86) (25 MCZ, NHM, NMW, PNG, ZSM); Marawaka, Ande ,, 1700 – 1800 m, 7 ° 1.697 ' S, 145 ° 49.807 ' E, 9 xi 2006, Balke & Kinibel (PNG 87) (2 ZSM); Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (1 NHM); Okapa, under stones in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 186) (8 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (2 NHM); Umg. [= environs of] Joginofi [? = Iganofi], Mukafanka River, [GE est.] 1700 – 1900 m, 6 ° 17 ' S, 145 ° 41 ' E, 13 vi 1979, W. G. Ullrich (6 MHNG); Umg. [= environs of] Kainantu, Onerunka, [GE est.] 1500 – 1700 m, 6 ° 17 ' S, 145 ° 52 ' E, 3 ii 1980, W. G. Ullrich (2 MHNG); same locality, 16 ii 1980, W. G. Ullrich (16 MHNG); same locality, 24 ii 1980, W. G. Ullrich (8 MHNG); Umg. [= environs of] Onerunka, Ramu River, [GE est.] 1500 – 1700 m, 6 ° 20 ' S, 145 ° 47 ' E, 13 vi 1979, W. G. Ullrich (14 MHNG); same locality, 18 vi 1979, W. G. Ullrich (1 MHNG); same locality, 9 xii 1979, W. G. Ullrich (7 MHNG); same locality, 1 – 30 iii 1980, W. G. Ullrich (3 MHNG); Waisa, nr. Okapa, in holes in partly burnt and decayed logs in small fast river, 1524 m, 6 ° 38 ' S, 145 ° 32 ' E, 15 ii 1965, M. E. Bacchus (MEB 192) (14 NHM); Waisa, nr. Okapa, in holes under stones in small fast river, 1524 m, 6 ° 38 ' S, 145 ° 32 ' E, 15 ii 1965, M. E. Bacchus (MEB 192 a) (24 NHM); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (3 NHM); Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (17 NHM); Wanitabi Valley, nr. Okapa, on partly rotted floating logs, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 176 a) (1 NHM); Wapi Creek, Kimiagomo, Okapa, ex debris and submerged logs in creek, 1900 m, 6 ° 25 ' S, 145 ° 34 ' E, 9 viii 2005, K. Sagata (WB 123) (4 ZSM); Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (4 ZSM); Madang Province: Simbai area, 1200 m, 5 ° 13.389 ' S, 144 ° 37.285 ' E, 10 iii 2007, Kinibel (PNG 152) (3 ZSM); Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (1 NMW); Herzog Mts., Vagau [Wagau], ex dead leaves in small stream in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 139) (4 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (2 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small stream in dense primary forest, 1680 m, 6 ° 48 ' S, 146 ° 48 ' E, 12 i 1965, M. E. Bacchus (MEB 149 a) (20 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in small stream in dense primary forest, 1680 m, 6 ° 48 ' S, 146 ° 48 ' E, 12 i 1965, M. E. Bacchus (MEB 149) (4 NHM); Kaindi (Wau), [GE est.] 1200 – 1400 m, 7 ° 20 ' S, 146 ° 42 ' E, 6 xii 1978, L. Deharveng (2 MHNG); Lae – Bulolo road, Gurakor Creek, ex gravel banks, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 133) (3 NHM); Markham Valley, Gusap, 90 miles NW of Lae, ex small muddy pools in almost dry stream bed, much algae, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 158) (1 NHM); Western Highlands Province: Kundum, 1400 m, 5 ° 16.096 ' S, 144 ° 27.869 ' E, 3 iii 2007, Kinibel (PNG 142) (22 MCZ, NHM, NMW, PNG, ZSM); Simbai, 1800 – 2000 m, 5 ° 14.276 ' S, 144 ° 28.741 ' E, 1 iii 2007, Kinibel (PNG 138) (51 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	diagnosis	Differential diagnosis. Quite similar in dorsal habitus to H. ambroides and H. ambripes (Figs. 10, 11, 14); differing from H. ambroides by the bicolored head, the less strongly punctate dorsum, and the larger size (ca. 1.82 vs. 1.71 mm); differing from H. ambripes by the confluent pronotal foveae PF 2, the differently shaped pronotum (PA greater than PB), the longer elytra, and the larger size (ca. 1.82 vs. 1.76 mm). Males of H. ambra are distinguished from males of both compared species by the widened mesotibiae. The male genitalia of the three species (Figs. 12, 13, 16) clearly show a relationship; among other differences, in H. ambra the left paramere differs from that of H. ambripes, and the right paramere differs from that of H. ambroides.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.82 / 0.75; head 0.30 / 0.38; pronotum 0.41 / 0.50, PA 0.42, PB 0.39; elytra 1.11 / 0.75. Dorsum amber colored, head bicolored, frons darker than clypeus and labrum, legs light brown, maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward slightly at posterior angles; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures denser at anterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 well impressed, oval, oblique, very shallowly confluent in middle, conjointly forming U-shaped impression; PF 3 and PF 4 moderately deep. Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1.5 / 6 / 5. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. as 3 / 2, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques narrow, slightly arcuate, slightly converging toward one another anteriorly, weakly raised, weakly carinate laterally, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS and adjacent area on first ventrite conjointly forming shallow concavity; AIS width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slender, straight. Mesotibia slightly widened on medial surface near distal 2 / 3. Metatibia slender, straight. Abdominal apex symmetrical. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 388).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	etymology	Etymology. Named in reference to the color and transparency of the cuticle.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B77FF87FF79F523FEEAFC82.taxon	distribution	Distribution. With a wide geographical distribution, present in six Areas; usually collected at 1200 m or higher (Fig. 431).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	description	(Figs. 11, 13, 274 – 279, 433)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (NHM). Paratypes (14): Eastern Highlands Province: Okapa, on logs and vegetable debris in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 187 a) (3 NHM); Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (5 MCZ, NHM, NMW, PNG, ZSM); Madang Province: Same data as holotype (4 NHM); Sandaun Province: Sokamin, ex leaves and rotting wood in stream, 1200 m, 4 ° 51.883 ' S, 141 ° 37.534 ' E, 20 x 2003, K. Sagata (WB 13) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	diagnosis	Differential diagnosis. Quite similar in dorsal habitus to H. ambra and H. sagatai (Figs. 10, 11, 15); differing from H. ambra by the non-confluent pronotal foveae PF 2, the differently shaped pronotum (PA and PB equal), the shorter elytra, and the smaller size (ca. 1.76 vs. 1.82 mm); differing from H. sagatai by the more strongly punctate pronotum, the median concavity of the first sternite, and the larger size (ca. 1.76 vs. 1.65 mm); males of H. ambripes are distinguished from males of both compared species by the markedly modified protibiae. The aedeagus of H. ambripes is most similar to that of H. ambra, but the two consistently differ in significant details (Figs. 12, 13). The metaventrite and very complicated leg chaetotaxy are illustrated with SEMs (Figs. 274 – 279).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.76 / 0.74; head 0.30 / 0.33; pronotum 0.41 / 0.51, PA 0.39, PB 0.38; elytra 1.07 / 0.74. Dorsum amber colored, head bicolored, frons darker than clypeus and labrum, legs light brown, maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward very slightly, if at all, at posterior angles; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures larger and denser at anterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 moderately deep, oval, not confluent in middle; PF 3 and PF 4 moderately deep. Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1.5 / 6 / 5. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. as 3 / 2, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques narrow, slightly arcuate, slightly converging toward one another anteriorly, weakly raised, weakly carinate laterally, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS and adjacent area on first ventrite conjointly forming shallow concavity; AIS width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia markedly excavate on medial margin in distal 1 / 2. Mesotibia much narrower in distal 1 / 5 than at midlength. Metatibia gradually thickened from base to about distal 3 / 4, then markedly narrowed. Abdominal apex symmetrical.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	etymology	Etymology. Named in reference to the amber color and sexually dimorphic legs.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B71FF86FF79F14AFDA2FD16.taxon	distribution	Distribution. Currently known from four localities, three in Area 1 (at both the west and east ends) and one in Area 5; elevation range 1200 – 1524 m (Fig. 433). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	description	(Figs. 14, 16, 432)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (NHM). Paratypes (180): Eastern Highlands Province: Okapa, on logs and vegetable debris in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 187 a) (15 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (1 NHM); Umg. [= environs of] Igipinti, Korindaiop River, [GE est.] 600 – 1700 m, 6 ° 25 ' S, 145 ° 42 ' E, 18 vi 1979, W. G. Ullrich (18 MHNG); Umg. [= environs of] Kainantu, Onerunka, [GE est.] 1500 – 1700 m, 6 ° 17 ' S, 145 ° 52 ' E, 24 ii 1980, W. G. Ullrich (3 MHNG); Umg. [= environs of] Okapa, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 18 vi 1979, W. G. Ullrich (6 MHNG); Umg. [= environs of] Onerunka, Ramu River, [GE est.] 1500 – 1700 m, 6 ° 20 ' S, 145 ° 47 ' E, 9 xii 1979, W. G. Ullrich (6 MHNG); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (38 NHM); Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (7 NHM); Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (1 NHM); Wanitabi Valley, nr. Okapa, on partly rotted floating logs, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 176 a) (41 NHM); Wapi Creek, Kimiagomo, Okapa, ex debris and submerged logs in creek, 1900 m, 6 ° 25 ' S, 145 ° 34 ' E, 9 viii 2005, K. Sagata (WB 123) (3 ZSM); Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (3 ZSM); Madang Province: Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel bank of small river in places where rotten leaves had accumulated, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 73) (4 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (1 NHM); Western Highlands Province: Sepik River Basin, Kil Stream, montane forest, 1800 m, 5 ° 40 ' S, 144 ° 42 ' E, 1 vii – 30 viii 1988, D. Dudgeon (11 NMW); same locality, 16 viii 1988, D. Dudgeon (22 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	diagnosis	Differential Diagnosis. Quite similar in dorsal habitus to H. ambra and H. ambripes (Figs. 10, 11, 14); differing from H. ambra by the unicolored head, the more strongly punctate dorsum, and the smaller size (ca. 1.71 vs. 1.82 mm); differing from H. ambripes by the confluent pronotal foveae PF 2, the differently shaped pronotum, and the longer elytra. Males of H. ambroides are distinguished from males of H. ambra by the non-modified mesotibiae, and from those of H. ambripes by the non-modified protibia. The male genitalia of the three species (Figs. 12, 13, 16) clearly show a relationship; among other differences, the aedeagus of H. ambroides can be recognized by the very differently shaped right paramere.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.71 / 0.73; head 0.25 / 0.38; pronotum 0.40 / 0.48, PA 0.40, PB 0.41; elytra 1.07 / 0.73. Dorsum varying from amber colored with dark brown head and pronotal fascia to entirely dark brown with piceous head and pronotal disc, head not bicolored, legs light brown in amber individuals, brown in darker individuals, maxillary palpi brown to testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate and shining medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward slightly at posterior angles; punctures on disc ca. 1 – 2 xpd those of frons, interstices shining, 1 – 4 xpd, punctures much larger and much denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 deep, oval, oblique, very shallowly confluent in middle, conjointly forming U-shaped impression; PF 3 and PF 4 moderately deep. Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 7 / 5. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. as 3 / 2, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques narrow, slightly arcuate, converging toward one another anteriorly, weakly raised, weakly carinate laterally, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS and adjacent area on first ventrite conjointly forming shallow concavity; AIS width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; all tibiae slender, straight. Abdominal apex symmetrical.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	etymology	Etymology. Named in reference to relationship to H. ambra.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B70FF85FF79F0FEFADDFC5E.taxon	distribution	Distribution. Currently known from Areas 1 (eastern), 5, and 6; elevation range 1000 – 1900 m (Fig. 432).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	description	(Figs. 15, 17, 435)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: Abau River, ex plant debris, 1571 m, 4 ° 50.782 ' S, 141 ° 38.132 ' E, 13 x 2003, K. Sagata (WB 48) (ZSM). Paratypes (4): Sandaun Province: Same data as holotype (2 ZSM); May River, ex leaves and rotting wood in stream, 1718 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 8 x 2003, K. Sagata (WB 46) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	diagnosis	Differential Diagnosis. Quite similar in dorsal habitus to H. ambripes and H. essentia (Figs. 11, 15, 18); differing from H. ambripes by the confluent pronotal foveae PF 2, the more finely punctate pronotum, and the smaller size (ca. 1.65 vs. 1.76 mm); differing from H. essentia by the more finely punctate pronotum, and the shallower pronotal foveae. Males of all three species have modified protibiae, those of H. sagatai being the least strongly modified. The aedeagus of H. sagatai is most similar to that of H. essentia, but the two consistently differ in significant details (Figs. 17, 20).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.65 / 0.68; head 0.27 / 0.34; pronotum 0.36 / 0.47, PA 0.35, PB 0.35; elytra 1.02 / 0.68. Dorsum amber colored, head bicolored, frons darker than clypeus and labrum, legs and maxillary palpi light brown. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward slightly at posterior angles; punctures on disc slightly smaller and sparser than those of frons, interstices shining, 2 – 6 xpd, punctures larger and denser at anterior ca. 1 xpd; PF 1 united to form very shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 moderately deep, oval, oblique, very shallowly confluent in middle, conjointly forming faint U-shaped impression; PF 3 and PF 4 moderately deep. Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 4 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 7 / 5. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques moderately narrow, slightly arcuate, converging toward one another anteriorly, weakly raised, located at sides of deep median depression. Metaventrite with very low and very short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS weakly concave, width at straight posterior margin ca. 2 x P 2. Profemur (male) with moderately large, sharply pointed tubercle next to trochanter; protibia emarginate on medial surface in distal 1 / 2. Mesotibia simple. Metatibiae slender, very weakly emarginate on medial margin near midlength. Abdominal apex symmetrical.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	etymology	Etymology. Named in honor of Papuan biologist Katayo Sagata, the collector of this and other new species of PNG Hydraena.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B73FF84FF79F631FC13FD32.taxon	distribution	Distribution. Currently known only from two very narrowly separated localities in Saundaun Province: in the western extreme of Area 1; elevations 1571 m and 1718 m (Fig. 435).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	description	(Figs. 18, 20, 434)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Sepik River Basin, stream beside milestone labelled G- 99, unshaded stream with angular boulders, some coated with java moss, 1540 m, 6 ° 18 ' S, 145 ° 55 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes (12): Eastern Highlands Province: Same data as holotype (7 NMW); Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (5 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	diagnosis	Differential Diagnosis. Quite similar in dorsal habitus to H. ambripes and H. sagatai (Figs. 11, 15, 18); differing from both species by the more coarsely punctate dorsum and deeper pronotal foveae; additionally differing from H. ambripes by the smaller size (ca. 1.64 vs. 1.76 mm), and the differently shaped male metatibiae. Males of all three species have modified protibiae, those of H. essentia being the most strongly modified. The aedeagus of H. essentia is most similar to that of H. sagatai, but the two consistently differ in significant details, especially in the greatly reduced state of H. essentia (Figs. 17, 20).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.64 / 0.69; head 0.25 / 0.34; pronotum 0.34 / 0.46, PA 0.37, PB 0.35; elytra 1.04 / 0.69. Dorsum amber colored, head bicolored, frons darker than clypeus and labrum, legs light brown, maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward very slightly, if at all, at posterior angles; punctures on disc ca. 1 – 2 xpd those of frons, interstices shining, 1 – 2 xpd, punctures denser at anterior; PF 1 narrowly separated one from the other by very low ridge (no present in all specimens); PF 2 deep, oval, oblique, not confluent; PF 3 and PF 4 moderately deep. Elytra distinctively humped just behind midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1.5 / 6 / 4. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques narrow, slightly arcuate, slightly converging toward one another anteriorly, weakly raised, located at sides of deep, median depression. Metaventrite with strong midlongitudinal ridge between mesoventral intercoxal process and median depression, also with short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia markedly emarginate on medial surface in distal 1 / 2. Meso- and metatibiae very slender, straight. Abdominal apex symmetrical.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	etymology	Etymology. Named in reference to the markedly reduced aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B72FF8BFF79F0DAFEDCFF6E.taxon	distribution	Distribution. Currently known from two localities near the eastern limit of Area 1; elevations 1400 m and 1540 m (Fig. 434).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	description	(Figs. 19, 21, 436)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Clear stream, summit of Kassem Pass at forest level, 1450 m, 6 ° 18 ' S, 145 ° 52 ' E, 27 vii 1975, R. W. Hornabrook (NMNZ). Paratypes (54): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 2400 m, 5 ° 55.615 ' S, 145 ° 22.699 ' E, 23 xi 2006, Balke & Kinibel (PNG 107) (1 ZSM); Akameku – Brahmin, Bismarck Range ,, 2200 m, 5 ° 56.801 ' S, 145 ° 22.238 ' E, 23 xi 2006, Balke & Kinibel (PNG 106) (8 MCZ, NHM, NMW, PNG, ZSM); Clear stream, summit of Kassem Pass at forest level, 1450 m, 6 ° 18 ' S, 145 ° 52 ' E, 27 vii 1975, R. W. Hornabrook (9 NMNZ); Western Highlands Province: Mondmill, 5 km SE Minj, small pools near creek, 1740 m, 5 ° 56.801 ' S, 144 ° 39.898 ' E, 12 vi 2006, John (PNG 77) (5 NMNZ); Sepik River Basin, Waré Creek, partially shaded montane stream with angular, moss – covered boulders, small waterfalls and pools, 2000 m, 5 ° 42 ' S, 144 ° 39 ' E, 1 vii – 30 viii 1988, D. Dudgeon (31 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	diagnosis	Differential Diagnosis. Similar to H. ambroides in size (ca. 1.71 – 1.74 mm), unicolored head, and males lacking distinctively modified legs; differing therefrom by the much more prominent dorsal setae, the slightly smaller eyes, the slightly smaller pronotum, and the more strongly arcuate elytral margins (Figs. 11, 19). The aedeagi of the two species distinctively differ (Figs. 16, 21).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.74 / 0.73; head 0.28 / 0.37; pronotum 0.38 / 0.47, PA 0.39, PB 0.39; elytra 1.05 / 0.73. Dorsum dark brown to piceous, head and disc of pronotum darkest, head not bicolored, legs and maxillary palpi brown. Eyes comparatively small, rather coarsely faceted. Pronotum rather small compared with size of elytra. Dorsal setae prominent, especially on pronotum. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum very sparsely very finely punctate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; lateral margins turning outward slightly at posterior angles; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures larger and denser at anterior and posterior; PF 1 united to form transverse impression across anterior 1 / 3 of pronotal disc; PF 2 deep, oval, oblique, very shallowly confluent in middle; PF 3 and PF 4 deep. Elytra distinctively humped at midlength, at summit of posterior declivity; lateral margins evenly arcuate; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 7 / 5. P 1 narrow, not laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to raised mesoventral intercoxal process. Plaques moderately narrow, slightly arcuate, converging toward one another anteriorly, weakly raised, located at sides of deep median depression. Metaventrite with very low and very short midlongitudinal ridge between mesoventral intercoxal process and median depression, also with short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS weakly concave, width at straight posterior margin ca. 2 x P 2. All femora very slender. Profemur (male) with moderately large, sharply pointed tubercle next to trochanter; protibia very slender, very slightly emarginate on medial surface. Meso- and metatibiae slender, widest at midlength. Abdominal apex symmetrical.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	etymology	Etymology. Named in reference to the relatively (for the Ambra group) hairy dorsum, and relationship to H. ambra (pilula = hair; diminutive).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7DFF8BFF79F361FA84F8F8.taxon	distribution	Distribution. Currently known only from Area 1 (eastern); elevation range 1450 – 2400 m (Fig. 436).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF8AFF79F2BAFAD5FCE9.taxon	description	The female tergite X, gonocoxite, and spermatheca of H. manulea and H. phainops are illustrated (Figs. 389, 390). The tergite X and gonocoxite of these two species are quite similar, whereas the spermathecae differ to a greater degree. More study, including DNA sequencing, is needed to determine if this group is composite. Members of this group have been collected at a wide elevation range, 10 – 1800 m, with many intermediate elevation records (maps Figs. 439 – 442, 444 – 449). The most widely collected species in the group, H. manulea, has an elevation range of 10 – 1800 m. Species in this group are typically found in gravel banks of streams and rivers.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	description	(Figs. 22, 24, 280 – 283, 389, 439)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae, Buins Creek, muddy gravel banks of large slow river, [GE est.] 10 – 30 m, 6 ° 43 ' S, 146 ° 59 ' E, 27 xii 1964, M. E. Bacchus (MEB 122) (NHM )). Paratypes (880): East Sepik Province: Prince Alexander Mts., Wewak – Maprik, 100 m, 3 ° 43.013 ' S, 143 ° 37.665 ' E, 21 iv 2006, Balke (PNG 47) (1 ZSM); Eastern Highlands Province: Bottom of Kassem Pass, [GE est.] 1600 – 1700 m, 6 ° 18 ' S, 145 ° 52 ' E, 6 ix 1975, R. W. Hornabrook (5 NMNZ); Madang Province: 4 km SW Gogal River & Lae Highway Crossing, [GE est.] 50 – 100 m, 4 ° 58 ' S, 145 ° 47 ' E, 10 iii 1991, D. Larson (1 MCZ); Aiome area, 130 m, 5 ° 10.593 ' S, 144 ° 42.8 ' E, 11 iii 2007, Kinibel (PNG 156) (11 MCZ, NHM, NMW, PNG, ZSM); Gogal Valley, 6 km S Baru, [GE est.] 300 – 500 m, 5 ° 43 ' S, 146 ° 32 ' E, 10 iv 1991, D. Larson (2 MCZ); Highway near Madang, ford, 80 m, 5 ° 24.405 ' S, 145 ° 38.213 ' E, 26 xi – 3 xii 2006, Binatang Boys (PNG 117) (27 MCZ, NHM, NMW, PNG, ZSM); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (6 MCZ, NHM, NMW, PNG, ZSM); Madang, Ohu Village, 160 m, 5 ° 13.923 ' S, 145 ° 40.763 ' E, 30 iv 2006, Balke & Sagata (PNG 49) (3 ZSM); Ramu Valley, 2 km SE Brahman, [GE est.] 130 – 150 m, 5 ° 43 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (23 MCZ); Ramu Valley, 4 – 5 km SW Yagumbu, [GE est.] 400 – 600 m, 5 ° 38 ' S, 145 ° 31 ' E, 15 iv 1991, D. Larson (1 MCZ); Ramu Valley, Mum River at Brahman, [GE est.] 130 – 150 m, 5 ° 42 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (3 MCZ); Ramu Valley, Sare River, 4 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (4 MCZ); Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (118 NMW); Sepik-Ramu Basin, Mom Creek, substrate of smooth cobbles set in coarse sand, loosely packed, 20 % shaded, water shallow, 170 m, 5 ° 45 ' S, 145 ° 20 ' E, 1 vi – 30 vii 1988, D. Dudgeon (1 NMW); Morobe Province: 3 miles Bulolo – Lae road, ex mud banks of small stream, [GE est.] 50 – 150 m, 6 ° 42 ' S, 146 ° 57 ' E, 29 xii 1964, M. E. Bacchus (MEB 128) (5 NHM); 5 miles W of Lae, Buins Creek, ex sand and gravel banks of clear fast river, [GE est.] 10 – 40 m, 6 ° 43 ' S, 147 ° 2 ' E, 28 xii 1965, M. E. Bacchus (MEB 121) (150 NHM); Bulolo River, east of Wau, 900 m, 7 ° 8 ' S, 146 ° 37 ' E, 15 x 1964, W. L. & J. G. Peters (2 CAS); Busu River, c. 5 m. N of Lae, ex muddy gravel banks of large river, [GE est.] 80 – 200 m, 6 ° 38 ' S, 147 ° 0 ' E, 21 i 1965, M. E. Bacchus (MEB 154 a) (30 NHM); same locality, 21 i 1965, M. E. Bacchus (MEB 154) (31 NHM); c. 7 mi. Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (14 NHM); Huon Pen., road to Kwapsanek, 250 m, 6 ° 30.27 ' S, 146 ° 59.581 ' E, 31 iii 2006, Balke & Sagata (PNG 24) (2 ZSM); Kassam Pass, Sing Sing Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 1 ' E, 14 vi 1979, W. G. Ullrich (33 MHNG); Kassam Pass, Yung Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 0 ' E, 8 v 1979, W. G. Ullrich (4 MHNG); same locality, 14 vi 1979, W. G. Ullrich (23 MHNG); Lae, Buins Creek, muddy gravel banks of large slow river, [GE est.] 10 – 30 m, 6 ° 43 ' S, 146 ° 59 ' E, 27 xii 1964, M. E. Bacchus (MEB 122) (20 NHM); Lae – Bulolo road, ex gravel banks of small, clear stream, much algae, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 131) (1 NHM); Lae – Bulolo road, ex muddy gravel bank of small shaded stream, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 125) (15 NHM); Lae – Bulolo road, ex stones and gravel bank of large river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 124) (164 NHM); Lae – Bulolo road, Peracles Creek, ex gravel banks of small steam, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 132) (5 NHM); Lae, Umg. [= environs of] Gebensis, Gorogias River, [GE est.] 20 – 30 m, 6 ° 44 ' S, 147 ° 0 ' E, 14 vi 1979, W. G. Ullrich (1 MHNG); Lae, Umg. [= environs of] Oomsis, Buang River, [GE est.] 20 – 30 m, 6 ° 53 ' S, 146 ° 57 ' E, 14 vi 1979, W. G. Ullrich (10 MHNG); Oro Province: Northern District, tributary Musa, in open river bed backwater, 300 m, 9 ° 20 ' S, 148 ° 55 ' E, 21 viii 1975, R. W. Hornabrook (6 NMNZ); Sandaun Province: Mianmin, river, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 192) (3 ZSM); Western Highlands Province: Jimi Valley, Sendiap Station, 500 – 600 m, 5 ° 20.728 ' S, 144 ° 27.401 ' E, 5 iii 2007, Kinibel (PNG 146) (13 MCZ, NHM, NMW, PNG, ZSM); Sepik River Basin, Kil Stream, montane forest, 1800 m, 5 ° 40 ' S, 144 ° 42 ' E, 16 viii 1988, D. Dudgeon (2 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	diagnosis	Differential Diagnosis. Very similar to H. manuloides in habitus, size, and shape of the male protibia (Figs. 22, 23). Reliable determinations will be based on close examination of the male genitalia (Figs. 24, 25); in H. manulea there is a finger-like process on the dorsal surface, none on the ventral surface, and the hook-like apical process is small compared with the lobe it emerges from; whereas in H. manuloides there are two finger-like processes, one dorsal and one ventral, and the hook-like process is larger compared with the lobe (among other detail differences). The ventral structures and the very complicated leg chaetotaxy are illustrated with SEMs (Figs. 280 – 283).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.41 / 0.60; head 0.23 / 0.34; pronotum 0.35 / 0.44, PA 0.37, PB 0.38; elytra 0.84 / 0.60. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5 / 16 / 3; elytra dark brown; legs and maxillary palpi light brown, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 2 / 7 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 1, sides converging toward blunt apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, located at sides of deep, median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 widened on anterior surface, medial margin apically with cluster of very short spines. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 24). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 389).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	etymology	Etymology. " Long sleeve, hence with cuff "; named in reference to the shape of the male protibia.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7CFF89FF79F1FFFC15F82E.taxon	distribution	Distribution. A widely distributed and rather commonly collected species, known from Areas 1 – 6 and 8; elevation range 10 – 1800 m, with most records below 1100 m (Fig. 439).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	description	(Figs. 23, 25, 440)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	materials_examined	Type Material. Holotype (male): Central Province: Port Moresby – Brown River road, ex gravel banks of small fast running stream, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 199 a) (NHM). Paratypes (263): Central Province: Kokoda, under stones, river side, 365 m, 8 ° 39 ' S, 147 ° 15 ' E, 1 – 30 viii 1933, L. E. Cheesman (577) (22 NHM); nr. Port Moresby, Sogeri Plateau, Musgrave River, ex dead leaves caught among rocks, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 b) (5 NHM); Port Moresby – Brown River road, ex gravel banks of large slow muddy river, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 198) (5 NHM); Port Moresby – Brown River road, ex gravel banks of small fast running stream, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 199 a) (19 NHM); Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (1 NHM); Ramu Valley, Sare River, 4 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (43 MCZ); Sepik-Ramu Basin, Mom Creek, substrate of smooth cobbles set in coarse sand, loosely packed, 20 % shaded, water shallow, 170 m, 5 ° 45 ' S, 145 ° 20 ' E, 1 vi – 30 vii 1988, D. Dudgeon (72 NMW); Morobe Province: c. 3 m. Lae – Busu road, ex gravel banks of small swift river, [GE est.] 50 – 70 m, 6 ° 41 ' S, 147 ° 0 ' E, 21 i 1965, M. E. Bacchus (MEB 155 a) (70 NHM); Lae, Umg. [= environs of] Oomsis, Buang River, [GE est.] 20 – 30 m, 6 ° 53 ' S, 146 ° 57 ' E, 15 vii 1979, W. G. Ullrich (23 MHNG); Oro Province: Northern District, Tanbugal Afore village, [GE est.] 300 – 500 m, 9 ° 7 ' S, 148 ° 23 ' E, 16 viii 1975, R. W. Hornabrook (3 NMNZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	diagnosis	Differential Diagnosis. Very similar to H. manulea in habitus, size, and shape of the male protibia (Figs. 22, 23). Reliable determinations will be based on close examination of the male genitalia (Figs. 24, 25); refer to the differential diagnosis of H. manulea.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.42 / 0.58; head 0.25 / 0.33; pronotum 0.34 / 0.42, PA 0.36, PB 0.38; elytra 0.85 / 0.58. Dorsum of head piceous; pronotum brown in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 13 / 3; elytra dark brown; legs and maxillary palpi light brown, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 6 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques moderately wide, converging anteriorly, roundly raised, located at sides of deep, median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, distal 1 / 3 slightly widened on anterior surface, medial margin apically with cluster of very short spines. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 25).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	etymology	Etymology. Named in reference to the relationship with H. manulea.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7EFF88FF79F2BAFB6BF8B1.taxon	distribution	Distribution. With a wide distribution pattern in eastern PNG, but without records from Area 1; found in Areas 2, 3, 5, 7, 8 and 11; elevation range 20 – 1265 m, but with only one record above 500 m (Fig. 440).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	description	(Figs. 26, 28, 448)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, Sare River, 4 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (MCZ). Paratypes (29): Madang Province: Aiome area, 130 m, 5 ° 10.593 ' S, 144 ° 42.8 ' E, 11 iii 2007, Kinibel (PNG 156) (22 MCZ, NHM, NMW, PNG, ZSM); Ramu Valley, Mum River at Brahman, [GE est.] 130 – 150 m, 5 ° 42 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (1 MCZ); Sepik-Ramu Basin, Mom Creek, substrate of smooth cobbles set in coarse sand, loosely packed, 20 % shaded, water shallow, 170 m, 5 ° 45 ' S, 145 ° 20 ' E, 1 vi – 30 vii 1988, D. Dudgeon (1 NMW); Sandaun Province: Bewani Stn., forest puddles at base of Bewani Mts., 300 m, 3 ° 5.13 ' S, 141 ° 10.227 ' E, 12 iv 2006, Balke & Sagata (PNG 38) (5 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	diagnosis	Differential Diagnosis. Among members of the Manulea group, similar in body shape to H. thumbelina (Figs. 26, 27); differing therefrom by the smaller size (ca. 1.33 vs. 1.40 mm), the narrower pronotal fascia (color bands ca. 6 / 10 / 5 vs. 4 / 15 / 4), the subserial to random discal elytral punctures, and the differently shaped metaventral plaques. The male genitalia of the two species distinctively differ (Figs. 28, 29).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.55; head 0.23 / 0.32; pronotum 0.32 / 0.40, PA 0.35, PB 0.34; elytra 0.81 / 0.55. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 10 / 5; elytra brown; legs light brown to testaceous; maxillary palpi testaceous, tip of palpus slightly darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin very slightly emarginate; punctures on disc ca. 1 – 2 xpd those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior; many punctures on disc subserial or random. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect separately rounded, in posterior aspect margins forming moderately deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 6 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, located at sides of deep, median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly wider than P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia arcuate, distal 1 / 3 slightly widened on anterior surface and on medial margin, medial margin apically with cluster of very short spines. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 28).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	etymology	Etymology. Named in reference to the geographical distribution.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8FFF79F2BAFBD9F9BD.taxon	distribution	Distribution. A lowland species, currently known from the Sepik-Ramu basin, Area 3, but very near the bor- der of Areas 4 in the west and Area 2 in the east; elevation range 130 – 300 m (Fig. 442).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	description	(Figs. 27, 29, 442)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, elev. 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (NHM). Paratypes (34): Central Province: Kokoda, under stones, river side, elev. 365 m, 8 ° 39 ' S, 147 ° 15 ' E, 1 – 30 viii 1933, L. E. Cheesman (577) (3 NHM); nr. Port Moresby, Sogeri Plateau, Musgrave River, ex dead leaves caught among rocks, elev. [est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 b) (1 NHM); Madang Province: Finisterre Mts., Naho River Valley, Budemu-Kikipei track, ex gravel banks of small stream, elev. 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 74) (1 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, elev. 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (7 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, elev. 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (9 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (2 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (11 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	diagnosis	Differential Diagnosis. Very similar to H. thumbelipes in habitus, size, and shape of the male protibia (Figs. 27, 30). The shapes of the male metatibiae differ in the two species: in H. thumbelipes the metatibia is expanded subapically (SEM Fig. 291), whereas in H. thumbelina the metatibia is weakly sinuate on the medial margin (Fig. 27). Reliable determinations will also be based on close examination of the quite similar male genitalia (Figs. 29, 32).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.40 / 0.53; head 0.24 / 0.33; pronotum 0.33 / 0.43, PA 0.36, PB 0.35; elytra 0.83 / 0.53. Dorsum of head piceous; pronotum brown in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 4 / 15 / 4; elytra brown; legs and maxillary palpi light brown to testaceous, tip of palpus not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2.5 / 8 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques large, very narrowly separated, more narrowly so at posterior than at anterior, weakly raised, each plaque tapering from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs moderately long and slender. Profemur (male) with tubercle next to trochanter; protibia slightly arcuate, medial margin widened in distal 1 / 3, apex with cluster of short spines. Mesotibia straight. Metatibia distal 2 / 3 emarginate on medial margin. Abdominal apex symmetrical, densely setose, penultimate tergite and ventrite fused; last tergite (male) notched. Aedeagus as illustrated (Fig. 29).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	etymology	Etymology. Named after the character of the childrens' book, who was shrunk to a very small size. Named in reference to the small body size of this species, and to the prominent cluster of spiniform setae that form a " thumb " near the apex of the male protibia.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B79FF8EFF79F453FE14FA72.taxon	distribution	Distribution. A moderately wide distribution in eastern PNG, found in Areas 5 – 7, and 11; elevation range 100 – 1220 m (Fig. 442).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	description	(Figs. 30, 32, 286 – 291, 441)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: Mianmin, river, elev. 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 192) (ZSM). Paratypes (94): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, elev. 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (1 ZSM); Madang Province: Aiome area, elev. 130 m, 5 ° 10.593 ' S, 144 ° 42.8 ' E, 11 iii 2007, Kinibel (PNG 156) (16 MCZ, NHM, NMW, PNG, ZSM); Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, elev. 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (28 NHM); Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, elev. 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (4 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of small fast river, elev. 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 37) (17 NHM); Sandaun Province: May River, ex river side pool, elev. 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (3 ZSM); Mianmin, elev. 670 m, 4 ° 53.292 ' S, 141 ° 34.118 ' E, 20 x 2008, S. Ibalim (PNG 191) (1 ZSM); Mianmin elev. 670 m, 4 ° 53.329 ' S, 141 ° 35.263 ' E, 22 x 2008, S. Ibalim (PNG 189) (3 ZSM); Mianmin, river, elev. 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (2 ZSM); Mianmin, elev. 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 192) (17 MCZ, NHM, NMW, PNG, ZSM); Mianmin, elev. 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (3 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	diagnosis	Differential Diagnosis. Very similar to H. thumbelina in habitus, size, shape of the metaventral plaques, and shape of the male protibia (Figs. 27, 30, 286 – 287). Hydraena thumbelipes is shorter but as wide as H. thumbelina (ca. 1.29 / 0.53 vs. 1.40 / 0.53). The shapes of the male metatibiae differ in the two species: in H. thumbelipes the metatibia is expanded subapically (SEM Fig. 291), whereas in H. thumbelina the metatibia is weakly sinuate on the medial margin (Fig. 27). Reliable determinations will also be based on close examination of the quite similar male genitalia (Figs. 29, 32). The metaventrite, abdominal apex, and very complicated chaetotaxy of the male tibiae are illustrated with SEMs (Figs. 286 – 291).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.29 / 0.53; head 0.21 / 0.33; pronotum 0.31 / 0.39, PA 0.34, PB 0.32; elytra 0.76 / 0.53. Dorsum of head piceous; pronotum dark brown to piceous except light brown to testaceous band across anterior border, ratios of color bands, as measured in midline, ca. 4 / 17; elytra dark brown; legs and maxillary palpi light brown, tip of palpus not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2.5 / 9 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 5 / 3, sides converging toward blunt apex. Plaques large, narrowly separated, more narrowly so at posterior than at anterior, weakly raised, each plaque slightly tapering from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs moderately long and slender. Profemur (male) with tubercle next to trochanter; protibia very slightly, if at all, arcuate, medial margin widened in distal 1 / 3, apex with cluster of short spines. Mesotibia very slightly arcuate. Metatibia distal 1 / 3 slightly widened on medial margin. Abdominal apex symmetrical, sclerites fused, densely setose; last tergite (male) notched. Aedeagus as illustrated (Fig. 32).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	etymology	Etymology. Named in reference to the modified metatibiae and the relationship to H. thumbelina.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B78FF8DFF79F41AFC00FA72.taxon	distribution	Distribution. Currently known from Areas 2 and 5; records seem to track Area 2 rather well; elevation range 130 – 1264 m, with only one of eleven records above 1100 m (Fig. 441).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	description	(Figs. 31, 33, 296 – 297, 322 – 323, 390, 445)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (NHM). Paratypes (186): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, ex dead leaves caught among rocks, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 b) (6 NHM); Port Moresby – Brown River road, ex gravel banks of large slow muddy river, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 198) (3 NHM); Port Moresby – Brown River road, ex gravel banks of small fast running stream, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 199 a) (1 NHM); East Sepik Province: Prince Alexander Mts., Wewak – Maprik, 100 m, 3 ° 43.013 ' S, 143 ° 37.665 ' E, 21 iv 2006, Balke (PNG 47) (5 ZSM); Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of small fast river, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 37) (2 NHM); Highway near Madang, ford, 80 m, 5 ° 24.405 ' S, 145 ° 38.213 ' E, 26 xi – 3 xii 2006, Binatang Boys (PNG 117) (8 MCZ, NHM, NMW, PNG, ZSM); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (3 ZSM); Keki – Sewan, Adelbert Mts., 300 m, 4 ° 40.558 ' S, 145 ° 27.187 ' E, 30 xi 2006, Binatang Boys (PNG 121) (19 MCZ, NHM, NMW, PNG, ZSM); Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (7 NMW); Morobe Province: 5 miles W of Lae, Buins Creek, ex sand and gravel banks of clear fast river, [GE est.] 10 – 40 m, 6 ° 43 ' S, 147 ° 2 ' E, 28 xii 1965, M. E. Bacchus (MEB 121) (68 NHM); c. 3 m. Lae – Busu road, ex gravel banks of small swift river, [GE est.] 50 – 70 m, 6 ° 41 ' S, 147 ° 0 ' E, 21 i 1965, M. E. Bacchus (MEB 155 a) (14 NHM); c. 7 mi. Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (8 NHM); Huon Pen., road to Kwapsanek, 250 m, 6 ° 30.27 ' S, 146 ° 59.581 ' E, 31 iii 2006, Balke & Sagata (PNG 24) (7 MCZ, NHM, NMW, PNG, ZSM); Kassam Pass, Sing Sing Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 1 ' E, 14 vi 1979, W. G. Ullrich (5 MHNG); Kassam Pass, Yung Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 0 ' E, 14 vi 1979, W. G. Ullrich (2 MHNG); Lae – Bulolo road, ex mud and muddy gravel by small shaded creek, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 135) (1 NHM); Lae – Bulolo road, ex stones and gravel bank of large river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 124) (1 NHM); Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (4 NHM); Lae – Bulolo road, Peracles Creek, ex gravel banks of small steam, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 132) (3 NHM); Lae, Umg. [= environs of] Oomsis, Buang River, [GE est.] 20 – 30 m, 6 ° 53 ' S, 146 ° 57 ' E, 14 vi 1979, W. G. Ullrich (17 MHNG); same locality, 15 vii 1979, W. G. Ullrich (1 MHNG); Markham Valley, Lae – Kainantu road, Erap River, ex gravel, [GE est.] 80 – 130 m, 6 ° 37 ' S, 146 ° 42 ' E, 26 i 1965, M. E. Bacchus (MEB 156) (1 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	diagnosis	Differential Diagnosis. Differentiated from other PNG members of the genus by the combination of the very small size (ca. 1.25 mm), the dark dorsum, and especially the very large metaventral plaques (Figs. 31, 296). The aedeagus distinctly differs from that of other members of the Manulea group (Fig. 33). The metaventrite, and the very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 296 – 297, 322 – 323).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.25 / 0.52; head 0.21 / 0.32; pronotum 0.29 / 0.38, PA 0.34, PB 0.33; elytra 0.76 / 0.52. Dorsum of head piceous; pronotum piceous except anterior margin slightly lighter; elytra dark brown; legs and maxillary palpi brown, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 5 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent. Elytra with posterior declivity very gradual, summit slightly past midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 8 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques very large, very narrowly separated, more narrowly so at posterior than at anterior, weakly raised. Metaventrite anteriorly with very low midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, gradually increasing in width from base to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 33). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 390).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	etymology	Etymology. " Bright eyes "; named in reference to the large, oval and brightly shining metaventral plaques.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B7BFF8CFF79F41AFD8BF82E.taxon	distribution	Distribution. A wide distribution pattern, from the western part of Area 4 to the southeastern part of Area 11, and including records in Areas 2, 3, and 5, but no records from Area 1; elevation range 10 – 1500 m, but with only two records above 1100 m (Fig. 445).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	description	(Figs. 34, 36, 449)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, ex stones and gravel bank of large river, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 124) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	diagnosis	Differential Diagnosis. Among members of the Manulea group, somewhat similar in body shape to H. mianminica (Figs. 34, 39); differing therefrom by the smaller size (ca. 1.44 vs. 1.67 mm), the darker dorsal coloration, and the larger and differently shaped metaventral plaques (ratios ca. 3 / 3 / 10 / 2 vs. 3 / 2 / 8 / 3). The male genitalia of the two species distinctively differ (Figs. 36, 41). In addition, in males of H. intensa the metatibiae have a brush of setae on the medial margin.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.44 / 0.57; head 0.23 / 0.34; pronotum 0.35 / 0.42, PA 0.36, PB 0.35; elytra 0.86 / 0.57. Dorsum of head piceous; pronotum dark brown in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 4 / 17 / 3; elytra dark brown; legs dark brown; maxillary palpi brown, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 2 – 4 xpd, anterolateral angles microreticulate. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, median 1 / 2 of anterior margin emarginate; punctures on disc slightly larger and deeper than those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 10 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w as ca. 5 / 3, sides converging toward blunt apex. Plaques very large, converging very slightly anteriorly, roundly raised, separated by median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin very slightly wider than P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex, medial margin apically with cluster of very short spines. Mesotibia slightly arcuate. Metatibia straight, gradually increasing in width from base to apex, distal 1 / 3 of medial margin with long hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 36).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	etymology	Etymology. " Stretched tight "; named in reference to the elongate body form, elongate and slender legs, and to the " stretched " process of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB3FF79F2BAFEDFFA4C.taxon	distribution	Distribution. Currently known only from the type locality at the far eastern limit of Area 3; elevation 900 – 1100 m (Fig. 449).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	description	(Figs. 35, 37, 444)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Okapa, gravel banks of deep fast river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 189 a) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	diagnosis	Differential Diagnosis. Recognized among members of the Manulea group by the combination of the large size (ca. 1.97 mm, others in group ca. 1.25 – 1.67 mm), the pronotal macula (others in group have a fascia or submacula), and the very narrow plaques (ratios ca. 4 / 1 / 8 / 5) (Fig. 35). The male genitalia distinctively differ from that of other members of the Manulea group (Fig. 37).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.97 / 0.81; head 0.30 / 0.41; pronotum 0.44 / 0.53, PA 0.44, PB 0.47; elytra 1.22 / 0.81. Dorsum of head dark brown; pronotum light brown around dark brown macula, ratios of color bands, as measured in midline, ca. 9 / 14 / 7; elytra brown; legs and maxillary palpi light brown, tip of palpus not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum micropunctulate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, median 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 absent; PF 2 shallow; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 8 / 5. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques very narrow, parallel, located at sides of deep, median depression, each plaque posteriorly raised in point. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin very slightly greater than P 2. All legs moderately long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia moderately arcuate. Mesotibia very slightly arcuate. Metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 37).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	etymology	Etymology. Named in reference to similarities to other species in the group, found near Okapa.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B45FFB2FF79F400FEB8FCCA.taxon	distribution	Distribution. Currently known only from the type locality at Okapa, eastern Area 1, at an elevation of 1524 m (Fig. 444).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	description	(Figs. 38, 40, 446)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, ex stones and gravel bank of large river, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 124) (NHM). Paratypes (22): Oro Province: Northern District, tributary Musa, in open river bed backwater, 100 – 300 m, 9 ° 20 ' S, 148 ° 55 ' E, 21 viii 1975, R. W. Hornabrook (22 NMNZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	diagnosis	Differential Diagnosis. Among members of the Manulea group, somewhat similar in body shape to H. mianminica (Figs. 38, 39); differing therefrom by the slightly wider elytra, the narrower pronotal fascia (color bands ca. 7 / 13 / 7 vs. 6 / 16 / 4), the coarser elytral punctation, and the slightly differently shaped metaventral plaques (ratios ca. 2 / 3 / 8 / 3 vs. 3 / 2 / 8 / 3). Males of H. trichotarsa have long brushes of setae on the meso- and metatarsi. The male genitalia of the two species distinctively differ (Figs. 40, 41).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.64 / 0.67; head 0.22 / 0.39; pronotum 0.41 / 0.50, PA 0.42, PB 0.43; elytra 0.95 / 0.67. Holotype teneral; mature specimen with dorsum of head piceous; pronotum brown in front of and behind dark brown fascia, ratios of color bands, as measured in midline, ca. 7 / 13 / 7; elytra brown to dark brown; legs brown; maxillary palpi light brown, tip of palpus darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin very slightly emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 very shallow; PF 2 shallow; PF 3 deep; PF 4 very shallow or absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 3 / 8 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 1, sides converging toward blunt apex. Plaques moderately wide, parallel, weakly raised, located at sides of deep, median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia arcuate, distal 1 / 3 slightly widened on anterior surface and slightly widened on medial margin, medial margin apically with cluster of very short spines. Meso- and metatibia moderately arcuate. Meso- and metatarsi with long hair-like setae beneath. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 40).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	etymology	Etymology. Named in reference to the prominent setae of the meso- and metatarsi, and to the relationship to H. tarsotricha.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B44FFB1FF79F182FBA7FE46.taxon	distribution	Distribution. Currently known only from two localities, one at the border of Areas 3 and 6 (Lae – Bulolo road) at 900 – 1100 m, and one at the border of Areas 8 and 9, at 100 – 300 m (Fig. 446). Note. The holotype (Fig. 38) is teneral; mature specimens are much darker.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	description	(Figs. 39, 41, 447)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: May River, ex river side pool, 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (ZSM). Paratypes (16): Sandaun Province: Same data as holotype (8 MCZ, NHM, NMW, PNG, ZSM); Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (3 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (5 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	diagnosis	Differential Diagnosis. Among members of the Manulea group, similar in body shape to H. thumbelina (Figs. 27, 39); differing therefrom by the larger size (ca. 1.67 vs. 1.40 mm), the straight anterior margin of the pronotum, the subserial to random discal elytral punctures, and the differently shaped metaventral plaques. The male genitalia of the two species distinctively differ (Figs. 29, 41).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.67 / 0.64; head 0.26 / 0.36; pronotum 0.39 / 0.47, PA 0.39, PB 0.37; elytra 0.98 / 0.64. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 16 / 4, posterior color band very faint; elytra dark brown; legs and maxillary palpi brown, tip of palpus slightly darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin straight; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 5 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior; many punctures subserial or random. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 8 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques moderately wide, parallel, weakly raised, located at sides of deep, median depression, each plaque tapering from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 widened on anteromedial margin and apically with cluster of very short spines. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 41).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	etymology	Etymology. Named in reference to the geographical distribution.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B47FFB1FF79F009FEEAF8B0.taxon	distribution	Distribution. Currently known only from a few localities at or near Mianmin. The elevation range, 700 – 990 m, places these records in the western part of Area 2, but very near higher elevations that would be considered Area 1 sites (Fig. 447).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	description	(Figs. 42, 44, 349 – 350, 391, 451)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (NHM). Paratypes (121): Eastern Highlands Province: Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (4 NHM); Umg. [= environs of] Onerunka, Ramu River, [GE est.] 1500 – 1700 m, 6 ° 20 ' S, 145 ° 47 ' E, 13 vi 1979, W. G. Ullrich (3 MHNG); Madang Province: Same data as holotype (65 NHM); Finisterre Mts., Naho River Valley, Budemu, ex sand and gravel banks of small stream, but only in the 20 yards that it is permanent, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 19 x 1964, M. E. Bacchus (MEB 62) (3 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel banks of small stream, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 74) (12 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel bank of small river in places where rotten leaves had accumulated, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 73) (20 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (3 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of small fast river, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 37) (6 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (5 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	diagnosis	Differential Diagnosis. The habitus is similar to that of H. nitidimenta (Figs. 42, 43); distinguished therefrom and from the other members of the Jubilata group by the deep pronotal foveae PF 2, the frons punctures being much coarser laterally than medially, and the comparatively short, tapering metaventral plaques. The metatibiae of males are straight in H. jubilata, and slightly arcuate in the three other members of the Jubilata group. The aedeagus (Fig. 44) distinctively differs from that of other members of the Jubilata group. The metaventrite, abdominal apex, and chaetotaxy of the metatibiae are illustrated with SEMs (Figs. 349 – 350).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.79 / 0.69; head 0.32 / 0.39; pronotum 0.43 / 0.48, PA 0.43, PB 0.39; elytra 1.05 / 0.69. Dorsum dark brown to piceous, except anterior ca. 1 / 6 of pronotum light brown, legs brown to slightly reddish brown; maxillary palpi brown to light brown. Frons punctures much finer and sparser on disc than next to eyes, ca. 0.5 xef on disc, 1.5 xpd laterally; interstices shining, 1 – 6 xpd on disc. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum similarly very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin very slightly emarginate, anterior angles sharply rounded; punctures on disc ca. 1 xpd largest punctures of frons, interstices weakly shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 shallow, separated by very low and indistinct midlongitudinal ridge; PF 2 deep, oval, oblique, not confluent, separated by narrow ridge; PF 3 deep; PF 4 shallow. Elytra transversely convex, summit of posterior declivity near or at midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 3.5 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to mesoventral midlongitudinal ridge. Plaques moderately wide, tapering anteriorly, parallel, weakly raised, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression. AIS width at straight posterior margin very slightly greater than P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight, with minute bump at apex on medial surface. Mesotibia straight. Metatibia straight, or nearly imperceptibly emarginate on medial surface in distal 1 / 2. Metatrochanter with minute tubercle (SEM Fig. 349). Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 44) main piece, in ventral aspect, slightly sinuate, with both right and left sides thick-walled, left side characteristically with large lobate process apically; both parameres, in lateral aspect, lobe-shaped distally, right as wide as or wider than left; left paramere slightly longer than right; right paramere lobe-shaped in distal 2 / 3, setae along nearly entire ventral margin, none at apical angle. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 391).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	etymology	Etymology. " Joyfully shouting "; named in reference to the smile-shaped depression of the pronotum, formed by the PF 2 foveae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B46FFB7FF79F0D1FDD2FC54.taxon	distribution	Distribution. Currently known from a moderately closely clustered group of localities in eastern Area 1 at 1500 – 1700 m, and Area 5 at 1080 – 1375 m (Fig. 451). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	description	(Figs. 43, 45, 452)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Koma River, tributary of Fio River, at rattan bridge crossing, ca. 2.6 km N by W of Herowana airstrip, washed from wet gravel at edge of large rainforest stream, 1400 m, 6 ° 36 ' S, 145 ° 11 ' E, 29 v 2004, N. Porch (ANIC). Paratypes (57): Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (30 MCZ, NHM, NMW, PNG, ZSM); Sandaun Province: May River, ex river side pool, 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (1 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (1 ZSM); Mianmin, river ,, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (22 MCZ, NHM, NMW, PNG, ZSM); Western Highlands Province: Lugup River, 1700 m, 5 ° 17.237 ' S, 144 ° 28.214 ' E, 4 iii 2007, Kinibel (PNG 143) (3 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	diagnosis	Differential Diagnosis. The habitus is similar to that of H. jubilata (Figs. 42, 43); differing therefrom by the shallow pronotal foveae PF 2, among other characters (see H. jubilata diagnosis). The shape of the pronotum differs from that of H. lassulipes and H. supina (Figs. 46, 47); however, the metaventral plaques and the slightly arcuate male metatibiae are quite similar in the three species. The aedeagus (Fig. 453) distinctively differs from that of other members of the Jubilata group, and should be examined for reliable determinations.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.84 / 0.71; head 0.29 / 0.39; pronotum 0.43 / 0.48, PA 0.41, PB 0.38; elytra 1.13 / 0.71. Dorsum dark brown to piceous, except anterior ca. 1 / 6 of pronotum light brown, legs brown to slightly reddish brown; maxillary palpi brown to light brown. Frons punctures ca. 1 xef; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum similarly nearly impunctate, strongly shining. Genae weakly raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 5 xpd, punctures much larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc, sometimes with nearly imperceptible low midlongitudinal ridge or narrow area lacking punctures; PF 2 shallow, oval, oblique, not confluent; PF 3 moderately deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 3.5 / 1.5. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to mesoventral midlongitudinal ridge. Plaques moderately wide, parallel, weakly raised, especially at lateral margins, located at sides of deep, median depression. Metaventrite with strong midlongitudinal ridge between mesoventral intercoxal process and median depression. AIS width at straight posterior margin ca. equal to P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly emarginate on medial surface in distal 1 / 2, emargination with row of setae, apex with small cluster of short stout setae on medial surface. Mesotibia straight. Metatibia slightly arcuate. Male fifth ventrite with pair of pits near midline. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 45) main piece, in ventral aspect, with right side characteristically thick-walled and with tiny point apically, left side with much larger angulate lobe; left paramere, in lateral aspect, lobe-shaped in distal 1 / 3; right paramere lobe-shaped in distal 1 / 2, setae along lower ventral margin, none at apical angle.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	etymology	Etymology. " Bright chin "; named in reference to the shining mentum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B41FFB6FF79F638FA92FCAE.taxon	distribution	Distribution. Currently known from Area 1, widely but sparsely distributed; elevation range 700 – 1700 m; the rather tight cluster of localities near Mianmin, at 700 – 1080 m, could be considered in Area 2 (Fig. 452).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	description	(Figs. 46, 48, 351, 392, 454)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (NHM). Paratypes (150): Eastern Highlands Province: Okapa, small algae filled puddle, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 188) (4 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (1 NHM); Umg. [= environs of] Okapa, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 18 vi 1979, W. G. Ullrich (3 MHNG); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (4 NHM); Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (2 NHM); Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (11 MCZ, NHM, NMW, PNG, ZSM); Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (1 ZSM); Morobe Province: Same data as holotype (117 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (1 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (6 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	diagnosis	Differential Diagnosis. The dorsal habitus is somewhat similar to that of H. supina (Figs. 46, 47); differing therefrom by the shape of the pronotum, with PA and PB being equal, and the sides not distinctively emarginate between the anterior angles and the widest part; differing additionally by the smaller size (ca. 1.77 vs. 1.90 mm). The metaventral plaques and the slightly arcuate male metatibiae are quite similar to those of H. supina and H. nitidimenta. The aedeagus (Fig. 48) distinctively differs from that of other members of the Jubilata group, and should be examined for reliable determinations. The complicated chaetotaxy of the metatibia is illustrated with an SEM (Fig. 351).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.77 / 0.71; head 0.29 / 0.36; pronotum 0.39 / 0.47, PA 0.42, PB 0.42; elytra 1.09 / 0.71. Dorsum dark brown to piceous, anterior margin of pronotum slightly lighter, legs and maxillary palpi brown. Frons punctures ca. 1 xef; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum finely sparsely punctate. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 5 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 shallow, oval, oblique, not confluent; PF 3 moderately deep; PF 4 obsolete. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 4 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to mesoventral midlongitudinal ridge. Plaques moderately wide, parallel, weakly raised, located at sides of deep, median depression. Metaventrite with short midlongitudinal ridge between mesoventral intercoxal process and median depression. AIS width at straight posterior margin very slightly greater than P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia weakly arcuate. Mesotibia straight. Metatibia moderately arcuate. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 48) main piece, in ventral aspect, with right side characteristically thick-walled and angulate; both parameres, in lateral aspects, wide in distal 1 / 2; left paramere only slightly longer than right; right paramere with cluster of setae at apical angle. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 392).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	etymology	Etymology. " Little weary foot "; named in reference to the very slender legs and relatively heavy body.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B40FFB5FF79F1A1FEDCFCA1.taxon	distribution	Distribution. Currently known from eastern Area 1 and from Area 6 (Herzog Mts.); elevation range 1000 – 1700 m (Fig. 454).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	description	(Figs. 47, 49, 453)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (NHM). Paratypes (102): Eastern Highlands Province: Headwaters of Fio River, 0.5 km downstream of river crossing on Herowana / Oke Lookout path, ca. 4.5 km N of Herowana airstrip, washed from margins of riverside still water pools in rainforest; gravel and cobble dominated microhabitats, but some muddy, 1500 m, 6 ° 35 ' S, 145 ° 11 ' E, 29 v 2004, N. Porch (1 ANIC); Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (10 NHM); Western Highlands Province: Kundum, 1400 m, 5 ° 16.096 ' S, 144 ° 27.869 ' E, 3 iii 2007, Kinibel (PNG 142) (4 ZSM); Mondmill, 5 km SE Minj, small pools near creek, 1740 m, 5 ° 56.801 ' S, 144 ° 39.898 ' E, 12 vi 2006, John (PNG 77) (2 ZSM); Simbai, 1800 – 2000 m, 5 ° 14.276 ' S, 144 ° 28.741 ' E, 1 iii 2007, Kinibel (PNG 138) (55 MCZ, NHM, NMW, PNG, ZSM); Simbai, Ineng River, 2000 m, 5 ° 14.943 ' S, 144 ° 32.818 ' E, 27 ii 2007, Kinibel (PNG 135) (9 MCZ, NHM, NMW, PNG, ZSM); Simbai, Kairong River, 1850 m, 5 ° 14.84 ' S, 144 ° 28.457 ' E, 2 iii 2007, Kinibel (PNG 139) (21 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	diagnosis	Differential Diagnosis. The habitus is somewhat similar to that of H. lassulipes (Figs. 46, 47); differing therefrom and from other members of the Jubilata group by the shape of the pronotum, having the sides rather distinctively emarginate between the anterior angles and the widest part; differing additionally by the comparatively large size (ca. 1.90 mm). The metasternal plaques and the slightly arcuate male metatibiae are quite similar to those of H. lassulipes and H. nitidimenta. The aedeagus (Fig. 49) distinctively differs from that of other members of the Jubilata group, and should be examined for reliable determinations.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.90 / 0.74; head 0.30 / 0.41; pronotum 0.44 / 0.52, PA 0.44, PB 0.43; elytra 1.16 / 0.74. Dorsum dark brown to piceous, anterior margin of pronotum slightly lighter, legs and maxillary palpi brown. Frons punctures ca. 1 xef; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum finely sparsely punctate. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin very slightly emarginate; anterior angles sharply rounded; lateral margin between anterior angle and widest point slightly emarginate; punctures on disc ca. 1 xpd those of frons, interstices strongly shining, 2 – 4 xpd, punctures larger, deeper and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 very shallow, oval, oblique, separated by ca. fovea width; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1.2 / 1 / 3.6 / 1.6. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to mesoventral midlongitudinal ridge. Plaques moderately wide, converging slightly anteriorly, weakly raised, located at sides of deep, median depression. Metaventrite with midlongitudinal ridge between mesoventral intercoxal process and median depression. AIS width at straight posterior margin slightly less than 2 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight, very slightly widened on medial margin in distal 1 / 4. Mesotibia very slightly arcuate. Metatibia moderately arcuate in distal 2 / 3. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 49) main piece, in ventral aspect, distinctively sinuate, with both right and left sides thickwalled, left side characteristically longer than right; both parameres, in lateral aspect, lobe-shaped distally; left paramere much longer than right; right paramere lobe-shaped in distal 1 / 2, setae along lower ventral margin, none at apical angle.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	etymology	Etymology. " Lying on the back "; named in reference to the curvature of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B43FFB4FF79F1ABFAD6FC82.taxon	distribution	Distribution. Currently known from the eastern half of Area 1; elevation range 1400 – 2000 m (Fig. 453).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	description	(Figs. 50, 52, 292 – 295, 393, 437)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of slow-running river, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 11 i 1965, M. E. Bacchus (MEB 148 b) (NHM). Paratypes (157): Central Province: Kokoda, under stones, river side, elev. 365 m, 8 ° 39 ' S, 147 ° 15 ' E, 1 – 30 viii 1933, L. E. Cheesman (577) (22 NHM); Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, elev. 800 m, 5 ° 50.021 ' S, 145 ° 24.664 ' E, 24 xi 2006, Balke & Kinibel (PNG 112) (6 MCZ, NHM, NMW, PNG, ZSM); Frigano, Mt. Michael, in bush stream, elev. [est.] 1600 – 1700 m, 6 ° 25 ' S, 145 ° 20 ' E, 1 – 30 vii 1975, R. W. Hornabrook (17 NMNZ); NE Kassam, 48 km E of Kainantu, elev. 1350 m, 6 ° 13 ' S, 146 ° 0 ' E, 1 – 30 x 1959, T. C. Maa (10 NHM); Gulf Province: Marawaka, near Ande, elev. 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (2 ZSM); Madang Province: Akameku – Brahmin, Bismarck Range, elev. 750 m, 5 ° 49.307 ' S, 145 ° 24.389 ' E, 25 xi 2006, Balke & Kinibel (PNG 114) (19 MCZ, NHM, NMW, PNG, ZSM); Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of slow-running river, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 4 – 17 i 1965, M. E. Bacchus (MEB 148 b) (8 NHM); Herzog Mts., Vagau [Wagau], 11 i 1965, M. E. Bacchus (MEB 148 b) (5 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (6 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of swift shallow clear river, elev. 1128 m, 6 ° 48 ' S, 146 ° 48 ' E, 4 – 17 i 1965, M. E. Bacchus (MEB 145 a) (41 NHM); Herzog Mts., Vagau [Wagau], 8 i 1965, M. E. Bacchus (MEB 145 a) (2 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (3 NHM); Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, elev. 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (1 NHM); Wagau, Herzog Mts., elev. 1150 m, 6 ° 51.067 ' S, 146 ° 48.068 ' E, 19 xi 2006, Balke & Kinibel (PNG 102) (15 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	diagnosis	Differential Diagnosis. Differentiated from the two other members of the Foliobba group by the " narrowwaisted " body form (TL / PB ca. 4.89 vs. 3.25 and 3.16), and the larger size (ca. 1.76 vs. 1.58 and 1.43 mm) (Figs. 50, 51, 54). Hydraena foliobba additionally differs from H. striolata and H. infoveola by having the metaventral plaques slightly larger, the mesotibiae straight instead of arcuate, and the male metatibiae shaped differently. The aedeagus very distinctly differs from that of the compared species (Figs. 52, 53, 56). The metaventrite, and the very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 292 – 295).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.76 / 0.69; head 0.28 / 0.39; pronotum 0.40 / 0.48, PA 0.42, PB 0.41; elytra 1.08 / 0.69. Dorsum of head piceous; pronotum testaceous in front of and very narrowly behind piceous fascia, ratios of color bands, as measured in midline, ca. 7 / 17 / 3; elytra dark brown; legs and maxillary palpi brown. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc slightly larger than those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent or obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually slightly smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 9 / 5. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, located at sides of deep, median depression. Metaventrite with short low ridge extended from each mesoventral coxal cavity. AIS width at straight posterior margin ca. 1.5 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex, with moderately long spine on medial surface at ca. distal 2 / 3. Mesotibia straight. Metatibia slightly emarginate on medial surface, except very slightly increased in width in apical 1 / 6 and here bearing row of short spines. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 52) distal piece with sharply pointed, slightly arcuate process on left side, and large, leaf-shaped process apically. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 393).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	etymology	Etymology. " Leaf decanter "; named in reference to the leaf-shaped apical process of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B42FFBBFF79F43FFE25F9E2.taxon	distribution	Distribution. With a moderately wide distribution, known from Areas 1 (eastern), 2, 6 and 7; elevation range 65 – 1700 m (Fig. 437).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	description	(Figs. 51, 53, 514)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	materials_examined	Type Material. Holotype (male): Oro Province: Northern District, Tanbugal Afore village, elev. [est.] 300 – 500 m, 9 ° 7 ' S, 148 ° 23 ' E, 16 viii 1975, R. W. Hornabrook (NMNZ). Paratypes: Same data as holotype (7 NMNZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	diagnosis	Differential Diagnosis. Among members of the Foliobba group, most similar in dorsal habitus to H. infoveola (Figs. 51, 54); differing therefrom by the smaller size (ca. 1.43 vs. 1.58 mm), the brown color bands on each side of the pronotal fascia (testaceous in H. infoveola), the slightly more impressed pronotal foveae PF 2, and the more narrowly separated metaventral plaques. Males of the two species are additionally differentiated by differences in the shapes of the tibiae, and by the striolate area on the fifth abdominal ventrite of H. striolata (Fig. 51). The aedeagi of the two species distinctively differ (Figs. 53, 56).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.43 / 0.58; head 0.25 / 0.34; pronotum 0.34 / 0.42, PA 0.36, PB 0.36; elytra 0.84 / 0.58. Dorsum of head piceous; pronotum light brown in front of and very narrowly behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 14 / 3; elytra dark brown; legs and maxillary palpi brown to dark brown. Frons punctures slightly larger than 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent or obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 7 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, located at sides of deep, median depression. Metaventrite with short low ridge extended from each mesoventral coxal cavity. AIS width at straight posterior margin ca. 1.5 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex. Mesotibia moderately arcuate, ca. to same degree as protibia. Metatibia straight. Fifth ventrite median area (male) striolate (with very fine, closely spaced, parallel impressed lines) (Fig. 51). Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 53) main piece with large, sharply pointed, markedly arcuate process on left side; distal piece large in both ventral and lateral views.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	etymology	Etymology. Named in reference to the striolate area on the male fifth abdominal ventrite.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4DFFBAFF79F4EAFBA0FB52.taxon	distribution	Distribution. Currently known only from the type locality, Tanbugal Afore village, in central Area 8, at or very near the border with Area 7; elevation 300 – 500 m (Fig. 514). Notes. The holotype has a very narrow groove across part of the occipital area of the head (Fig. 51); this groove, apparently an anomaly, is not present on the other specimens examined.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	description	(Figs. 54, 56, 438)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	materials_examined	Type Material. Holotype (male): Gulf Province: Marawaka, Mala, elev. 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (ZSM). Paratypes (27): Gulf Province: Same data as holotype (25 MCZ, NHM, NMW, PNG, ZSM); Marawaka, near Ande, elev. 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	diagnosis	Differential Diagnosis. Among members of the Foliobba group, most similar in dorsal habitus to H. striolata (Figs. 51, 54); differing therefrom by the larger size (ca. 1.58 vs. 1.43 mm), the testaceous color bands in front of and behind the pronotal fascia (brown in H. striolata), the proportionally larger pronotal fascia (color band ratios ca. 6 / 18 / 3 vs. 6 / 14 / 3), the absent, or nearly imperceptible pronotal foveae PF 2, and the more widely separated metaventral plaques. Males of the two species are additionally differentiated by differences in the shapes of the tibiae, and by the striolate area on the fifth abdominal ventrite of H. striolata. The aedeagi of the two species distinctively differ (Figs. 53, 56).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.58 / 0.68; head 0.23 / 0.38; pronotum 0.38 / 0.48, PA 0.42, PB 0.42; elytra 1.00 / 0.68. Dorsum of head piceous; pronotum testaceous in front of and very narrowly behind piceous fascia, ratios of color bands, as measured in midline, ca. 2 / 3 / 1; elytra dark brown; legs and maxillary palpi brown. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent or obsolete; PF 2 extremely shallow, nearly imperceptible; PF 3 moderately deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 7 / 5. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, slightly more so laterally than medially, located at sides of deep median depression. Metaventrite with short low ridge extended from each mesoventral coxal cavity. AIS width at straight posterior margin ca. 1.5 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex, with moderately long spine on medial surface at ca. distal 2 / 3. Mesotibia moderately arcuate, ca. to same degree as protibia, slightly thickened at distal 2 / 3. Metatibia very slightly arcuate, gradually increasing in width from base to apex, medial surface, with few moderately long spines in distal 1 / 4. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 56) distal piece with sharply pointed, slightly arcuate process on left side, and large, arm-shaped process apically.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	etymology	Etymology. Named in reference to the greatly reduced and absent pronotal foveae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4CFFB9FF79F73AFCF1FCCA.taxon	distribution	Distribution. Currently known only from two very narrowly separated sites near Marawaka, at the eastern extreme of Area 1; elevations 1000 m and 1400 m (Fig. 438).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	description	(Figs. 55, 57, 302, 303, 362, 363, 394, 456)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (NHM). Paratypes (189): Madang Province: Adelbert Mts., below Keki, 790 m, 4 ° 42.3 ' S, 145 ° 25.089 ' E, 5 v 2006, Balke & Manaono (PNG 53) (10 MCZ, NHM, NMW, PNG, ZSM); Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (25 NHM); Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (5 NHM); Finisterre Mts., Naho River Valley, Budemu, ex sand and gravel banks of small stream, but only in the 20 yards that it is permanent, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 19 x 1964, M. E. Bacchus (MEB 62) (11 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (3 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of small fast river, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 37) (2 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (5 NHM); Finisterre Mts., Naho River Valley, Damanti, ex small pool, probably permanent, in clay in dense shade, 1067 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 39) (6 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (4 NHM); Finisterre Mts., Naho River Valley, nr. Sewe, large flat area of wet gravel with small rivulets running through it, 1615 m, 5 ° 51 ' S, 146 ° 8 ' E, 15 xi 1964, M. E. Bacchus (MEB 95) (5 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex dead leaves in small stream in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 139) (4 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (32 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (1 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (70 NHM); Huon Pen., Kwapsanek, 850 m, 6 ° 34.913 ' S, 147 °. 526 ' E, 31 iii 2006, Balke & Sagata (PNG 25) (6 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. cheesmanae (Figs. 55, 59); differing therefrom in being slightly larger (ca. 1.46 vs. 1.37), in having a more coarsely punctate pronotum with PA slightly wider than PB (PA and PB equal in H. cheesmanae), and having the metaventral plaques slightly longer and closer together (ratios ca. 3 / 2 / 9 / 2 vs. 3 / 3 / 8 / 3). The male metatibiae differ very slightly in the two species, whereas the male genitalia differ distinctively in many details (Figs. 57, 61). The metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 302, 303, 362, 363).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.46 / 0.63; head 0.24 / 0.35; pronotum 0.36 / 0.44, PA 0.38, PB 0.40; elytra 0.87 / 0.63. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5 / 15 / 4; elytra dark brown; legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and anterior 1 / 2 of postmentum very sparsely very finely punctulate, shining; posterior 1 / 2 of postmentum effacedly micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc slightly larger and deeper than those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 9 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques large, diverging slightly from posterior to anterior, weakly transversely raised, at sides of deep median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, widest subapically, cluster of small spines on medial margin at this point. Mesotibia straight. Metatibia straight or near so, medial margin in distal 1 / 2 weakly emarginate and with few long setae that lie flat on cuticle in dry specimens. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 57). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 394).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	etymology	Etymology. " Resting bow "; named in reference to the extremely weakly arcuate male metatibiae, and to the relatively small aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4FFFBFFF79F4C7FD82FE8A.taxon	distribution	Distribution. Currently known from several localities in Area 5, and one locality (Herzog Mts.) in Area 6; elevation range 760 – 1615 m (Fig. 456).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	description	(Figs. 58, 60, 298 – 301, 369, 455)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of slow-running river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 11 i 1965, M. E. Bacchus (MEB 148 b) (NHM). Paratypes (162): Central Province: Kokoda, under stones, river side, 365 m, 8 ° 39 ' S, 147 ° 15 ' E, 1 – 30 viii 1933, L. E. Cheesman (577) (2 NHM); Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (2 ZSM); Bottom of Kassem Pass, [GE est.] 1600 – 1700 m, 6 ° 18 ' S, 145 ° 52 ' E, 6 ix 1975, R. W. Hornabrook (5 NMNZ); Kami River, Goroka, Eastern Highlands, [GE est.] 2000 – 2200 m, 6 ° 5 ' S, 145 ° 23 ' E, 23 vii 1965, R. W. Hornabrook (4 NMNZ); Okapa, gravel banks of deep fast river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 189 a) (1 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (62 NHM); Umg. [= environs of] Igipinti, Korindaiop River, [GE est.] 600 – 1700 m, 6 ° 25 ' S, 145 ° 42 ' E, 18 vi 1979, W. G. Ullrich (1 MHNG); Madang Province: Aiome area, 130 m, 5 ° 10.593 ' S, 144 ° 42.8 ' E, 11 iii 2007, Kinibel (PNG 156) (4 ZSM); Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (14 NHM); Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (7 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (2 NHM); Morobe Province: Bulolo River, east of Wau, 900 m, 7 ° 8 ' S, 146 ° 37 ' E, 15 x 1964, W. L. & J. G. Peters (1 CAS); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (4 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (33 NHM); Herzog Mts., Vagau [Wagau], Snake River, ex muddy gravel bands of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152 a) (2 NHM); Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (3 NHM); Kassam Pass, Yung Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 0 ' E, 8 v 1979, W. G. Ullrich (1 MHNG); Kassam Pass, Yung Creek, 14 vi 1979, W. G. Ullrich (9 MHNG); Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (2 NHM); Sandaun Province: Mianmin, 670 m, 4 ° 53.329 ' S, 141 ° 35.263 ' E, 22 x 2008, S. Ibalim (PNG 189) (1 ZSM); Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (1 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Otiarca group by the unicolored piceous pronotum and, in males, the uniquely modified metatibiae (Figs. 58, 299). The aedeagus shows some similarity in the shape of the base to that of H. otiarca, and some similarity in the distal piece shape to that of H. cheesmanae, while also having distinct unique form of parameres and distal piece (Figs. 57, 60, 61). The metaventrite, prosternum, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 298 – 301, 369).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.57 / 0.68; head 0.23 / 0.37; pronotum 0.39 / 0.48, PA 0.42, PB 0.42; elytra 0.97 / 0.68. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median ca. 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 3 xpd, punctures larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly before midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 9 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques large, parallel, weakly transversely raised, at sides of deep median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, widest subapically, cluster of small spines at this point, moderately long spine on medial surface at ca. distal 1 / 3. Mesotibia straight. Metatibia bent at midlength, distal 1 / 2 widened. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 60).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	etymology	Etymology. " Little oar foot "; named in reference to the shape of the male metatibia, which is widened and bent such that it recalls the appearance of an oar as it is pulled through the water.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B49FFBEFF79F342FE51FD12.taxon	distribution	Distribution. Widely distributed, and with a wide elevation range; known from Areas 1 – 3, and 5 – 7; elevation range 130 – 2200 m (Fig. 455).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	description	(Figs. 59, 61, 458)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	materials_examined	Type Material. Holotype (male): Central Province: Kokoda, under stones, river side, 365 m, 8 ° 39 ' S, 147 ° 15 ' E, 1 – 30 viii 1933, L. E. Cheesman (577) (NHM). Paratypes: Same data as holotype (21 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. otiarca (Figs. 55, 59); differing therefrom in slightly smaller size (ca. 1.37 vs. 1. 46), less coarsely punctate pronotum, with PA and PB equal (PA slightly wider than PB in H. otiarca), a slightly larger pronotal fascia, and having the metaventral plaques slightly shorter and more widely separated (ratios ca. 3 / 3 / 8 / 3 vs. 3 / 2 / 9 / 2). The male metatibiae differ very slightly in the two species, whereas the male genitalia differ distinctively in many details (Figs. 57, 61).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.37 / 0.59; head 0.19 / 0.34; pronotum 0.34 / 0.41, PA 0.35, PB 0.35; elytra 0.83 / 0.59. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 12 / 5; elytra dark brown; legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and anterior 1 / 2 of postmentum very sparsely very finely punctulate, shining; distal 1 / 2 of postmentum micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 3 xpd, punctures larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 8 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques large, converging slightly anteriorly, weakly transversely raised, at sides of deep median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, widest subapically, cluster of small spines on medial margin at apex, moderately long spine on medial surface at ca. distal 1 / 3. Mesotibia straight. Metatibia weakly bent at midlength, distal 1 / 2 slightly widened. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 61).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	etymology	Etymology. Named in honor of the intrepid Englishwoman entomologist and naturalist Lucy Evelyn Cheesman, who collected the only known specimens of this species — in 1933! During August of that year she collected a total of five species of Hydraena at Kokoda.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B48FFBEFF79F0FFFAC5F862.taxon	distribution	Distribution. Currently known only from the type locality, Kokoda, in Area 7; elevation 365 m (Fig. 458).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	description	(Figs. 62, 64, 450)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	materials_examined	Type Material. Holotype (male): Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (ZSM). Paratype: same data as holotype (1 male, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. cheesmanae; differing therefrom in larger size (ca. 1.56 vs. 1.37), and metaventral plaque shape, which are more widely separated and have raised lateral margins (Figs. 59, 62). The male metatibiae differ very slightly in shape in the two species, but H. marawaka has longer setae on the brush. The male genitalia of the two species also suggest a relationship, but differ distinctively in many details (Figs. 61, 64).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.56 / 0.64; head 0.23 / 0.36; pronotum 0.39 / 0.45, PA 0.39, PB 0.39; elytra 0.92 / 0.64. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 7 / 14 / 5; elytra dark brown; legs light brown; maxillary palpi testaceous, tip slightly darker. Frons punctures ca. 1 – 2 xef, larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum effacedly micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 8 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques large, converging slightly anteriorly, transversely raised, more so laterally than medially, located at sides of deep median depression, each plaque tapering slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight, widest subapically, cluster of small spines on anteromedial margin at this point, moderately long spine on medial surface at ca. distal 1 / 3. Mesotibia straight. Metatibia straight, medial margin in distal 1 / 2 emarginate and bearing sparse brush of long hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 64).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	etymology	Etymology. Named in reference to the known geographical distribution.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBDFF79F2BAFE2AFA0D.taxon	distribution	Distribution. Currently known only from the type locality near the eastern and southern limit of Area 1; elevation 1400 m (Fig. 450).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	description	(Figs. 63, 65, 457)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (ZSM). Paratypes (19): Eastern Highlands Province: Same data as holotype (5 ZSM); Sandaun Province: Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (1 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (1 ZSM); Mianmin, river ,, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 192) (11 MCZ, NHM, NMW, PNG, ZSM); Mianmin, river ,, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Otiarca group by the narrow, carinate plaques (plaque rations ca. 3 / 1 / 9 / 4) and, in males, the arcuate mesotibiae and the uniquely modified metatibiae (Fig. 63). The male genitalia distinctly differ from other members of the Otiarca group, being more elongate and, in lateral view, less angulate (Fig. 65).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.53 / 0.66; head 0.23 / 0.37; pronotum 0.38 / 0.47, PA 0.39, PB 0.41; elytra 0.92 / 0.66. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5 / 17 / 3; elytra dark brown; legs light brown; maxillary palpi testaceous, tip slightly darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum effacedly micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 1 / 2 of anterior margin emarginate; punctures on disc ca. 1 – 2 xpd those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly beyond midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 9 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very narrow, carinate, parallel, located at sides of deep median depression, each plaque tapering very slightly from posterior to anterior. Metaventrite without midlongitudinal ridge. AIS width at slightly arcuate posterior margin ca. 1.7 x P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, widest subapically, anteromedial margin with cluster of small spines just before apex, moderately long spine on medial surface at ca. distal 1 / 3. Mesotibia slightly arcuate. Metatibia markedly arcuate, distal 1 / 3 widened and with medial margin bearing brush of hair-like setae. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 65).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	etymology	Etymology. Named in reference to the six arcuate tibiae of males.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4BFFBCFF79F7C3FDBDFBEA.taxon	distribution	Distribution. Currently known from the Mianmin area (700 – 1080 m), and one locality at Akameku – Brahmin (700 m); because of the combination of location and elevation these sites are considered to be in Area 2, although they border on Area 1 (Fig. 457).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B4AFFA3FF79F6E2FAD4FD8E.taxon	description	Most of the species have very large plaques that are very narrowly separated, more narrowly separated posteriorly than anteriorly, which is unusual in the genus (e. g., Figs. 308, 309, 311). The pronotal foveae are reduced in all but two species: PF 1 and PF 4 are absent, and PF 2 is extremely shallow, obsolete. Several of the species are very similar in most characters, and will require examination of the male genitalia for reliable determinations. A characteristic feature of the aedeagus in this group is the shape of the left paramere, which is usually moreor-less oval in cross-section, very strong and stiff, and arches up and over the distal piece (e. g., Figs. 68, 69). Two species, H. penultimata and H. altapapua, have plaques shaped differently than the other species (Figs. 78, 83), and also have quite distinct male genitalia (Figs. 80, 85); these two species, however, have the characteristic arching left paramere and are therefore provisionally placed in the Tetana group. The female tergite X, gonocoxite, and spermatheca of H. tetana, H. tarsotricha, and H. biundulata are illustrated (Figs. 395 – 397); they are quite similar, with (as in the male genitalia) H. biundulata being slightly different from the other two species. Members of this group have been collected at an elevation range of 500 – 2680 m. Seven of the ten species have not been collected above 1700 m; the three other species have been collected at a range of 970 – 2680 m (maps Figs. 459 – 468). The distributions suggest that this is primarily an Area 1 group, with some species spreading to the Finisterre Mts. (Area 5) and the Herzog Mts. (Area 6); only one of the ten species in the group, H. huonica, is endemic to Area 5, and no species is endemic to Area 6. Most microhabitat data indicate gravel banks of streams or rivers, with a few pools or ponds mentioned. Representative microhabitat notations include the following: washed from margins of riverside still water pools in rainforest, gravel and cobble dominated microhabitats, but some muddy; muddy gravel banks of small shaded stream; gravel bank of small river in places where rotten leaves had accumulated; washed from margins of small pool of a steep, rocky, forest stream at confluence with river, gravel, cobbles, wet rock microhabitats; gravel banks of small clear river in dense forest; montane stream tumbled down among moss-covered rocks which alternated with short sandy runs in more level sections, almost completely shaded.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	description	(Figs. 66, 68, 304 – 307, 395, 461)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (NHM). Paratypes (176): Eastern Highlands Province: Mjairasa, Okapa, ex stones in waterfall spray, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 17 iii 1965, R. W. Hornabrook (1 NMNZ); Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (7 NHM); Okapa, gravel banks of deep fast river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 189 a) (3 NHM); Purosa Valley, nr. Okapa, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182) (41 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (3 NHM); Umg. [= environs of] Igipinti, Korindaiop River, [GE est.] 600 – 1700 m, 6 ° 25 ' S, 145 ° 42 ' E, 18 vi 1979, W. G. Ullrich (3 MHNG); Umg. [= environs of] Kainantu, Onerunka, [GE est.] 1500 – 1700 m, 6 ° 17 ' S, 145 ° 52 ' E, 16 vi 1979, W. G. Ullrich (8 MHNG); same locality, 21 viii 1979, W. G. Ullrich (14 MHNG); Umg. [= environs of] Onerunka, Ramu River, [GE est.] 1500 – 1700 m, 6 ° 20 ' S, 145 ° 47 ' E, 13 vi 1979, W. G. Ullrich (26 MHNG); same locality, 20 vi 1979, W. G. Ullrich (2 MHNG); Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (24 NHM); Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (1 NHM); Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (9 NHM); Finisterre Mts., Naho River Valley, Budemu, ex sand and gravel banks of small stream, but only in the 20 yards that it is permanent, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 19 x 1964, M. E. Bacchus (MEB 62) (3 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel banks of small stream, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 74) (1 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel bank of small river in places where rotten leaves had accumulated, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 73) (5 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (15 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex gravel banks of small fast stream, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 91) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	diagnosis	Differential Diagnosis. Similar to H. acumena in habitus, size, plaques, and some male sexual dimorphisms (tubercle on first abdominal ventrite, meso- and metatarsi with long hair-like setae (Figs. 66, 79); differing therefrom by slightly coarser dorsal punctation and shape of the male protibial apex. Reliable determinations of the two species will require examination of the aedeagi, which distinctively differ (Figs. 68, 81). Ventral structures, and the very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 304 – 307).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.70 / 0.69; head 0.27 / 0.38; pronotum 0.38 / 0.46, PA 0.40, PB 0.38; elytra 1.04 / 0.69. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures random. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 11 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight, distal 1 / 4 widened on anterior surface, apex with cluster of small spines, ventral margin with row of short spines on ridge, moderately long spine on medial surface at base of widened area. Mesotibia very slightly arcuate. Metatibia straight. Meso- and metatarsi with long hair-like setae along lower margin that lie flat on cuticle in dry specimens. First abdominal ventrite with large, sharply pointed tubercle in midline. Fifth abdominal ventrite not modified. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 68). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 395).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	etymology	Etymology. Named in reference to the prominently thickened, strong and stiff left paramere, and the strong tubercle on the first ventrite of males.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B55FFA2FF79F041FB81FC5E.taxon	distribution	Distribution. Currently known from a rather tight line of localities in eastern Area 1 (indicating a road, perhaps), and two localities in the Finisterre Mts. of Area 5; elevation range 1220 – 1700 m (Fig. 461). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	description	(Figs. 67, 69, 308 – 309, 314 – 315, 396, 459)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (NHM). Paratypes (26): Madang Province: Finisterre Mts., Naho River Valley, nr. Moro, walking on surface of dead leaves. Specimens pure white color when alive, 2134 m, 5 ° 50 ' S, 146 ° 7 ' E, 10 xi 1964, M. E. Bacchus (MEB 94) (4 NHM); Finisterre Mts., Naho River Valley, nr. Sewe, large flat area of wet gravel with small rivulets running through it, 1615 m, 5 ° 51 ' S, 146 ° 8 ' E, 15 xi 1964, M. E. Bacchus (MEB 95) (17 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (2 NHM); Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (2 NHM); Western Highlands Province: Simbai, 1800 – 2000 m, 5 ° 14.276 ' S, 144 ° 28.741 ' E, 1 iii 2007, Kinibel (PNG 138) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	diagnosis	Differential Diagnosis. Similar in habitus and some male sexual dimorphisms (no tubercle on first abdominal ventrite, fifth ventrite with transverse ridge, long hair-like setae on the meso- and metatarsi) to H. tricosipes (Figs. 67, 70); differing therefrom by the larger size (ca. 1.78 vs. 1.63 mm), the wider and longer plaques (ratios ca. 3 / 4 / 13 / 1 vs. 3 / 3 / 11 / 1). The male genitalia of the two species also show a relationship, but differ in shapes of the main piece, distal piece, and parameres (Figs. 69, 72). The metaventrite, the very complicated chaetotaxy of the tibiae, and the long setae of the metatarsi are illustrated with SEMs (Figs. 308 – 309, 314 – 315).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.78 / 0.68; head 0.29 / 0.37; pronotum 0.41 / 0.47, PA 0.41, PB 0.39; elytra 1.08 / 0.68. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures random. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 13 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight or very slightly arcuate, distal 1 / 3 widened on anterior surface, moderately long spine on medial surface at base of widened area. Mesotibia very slightly arcuate; mesotarsi with long, straight setae along lower margin. Metatibia straight or very slightly arcuate; metatarsi with long hair-like setae along lower margin. Fifth abdominal ventrite posteriorly markedly transversely raised. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 69). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 396).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	etymology	Etymology. " Hairy feet "; named in reference to the prominent setae of the meso- and metatarsi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B54FFA1FF79F631FE19FC82.taxon	distribution	Distribution. Currently known from Areas 1, 5, and 6, with only one or two localities in each; elevation range 1220 – 2135 m (Fig. 459).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	description	(Figs. 70, 72, 310 – 313, 460)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (NHM). Paratypes (60): Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (1 ZSM); Madang Province: Finisterre Mts., Naho River Valley, Moro, 1691 m, 5 ° 50 ' S, 146 ° 7 ' E, 30 x – 23 xi 1964, M. E. Bacchus (MEB 78) (8 NHM); Finisterre Mts., Naho River Valley, Moro, nr. Sewe, gravel bank of small stream running into River Naho, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 2 xi 1964, M. E. Bacchus (MEB 81) (44 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex tiny puddles left in clay bottom of partly ephemeral pool, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 92) (5 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (2 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	diagnosis	Differential Diagnosis. Similar in habitus and some male sexual dimorphisms (no tubercle on first abdominal ventrite, fifth ventrite with transverse ridge, long hair-like setae on the meso- and metatarsi) to H. tarsotricha (Figs. 67, 70); differing therefrom by the smaller size (ca. 1.63 vs. 1.78 mm), and the narrower and shorter plaques (ratios ca. 3 / 3 / 11 / 1 vs. 3 / 4 / 13 / 1). The male genitalia of the two species also show a relationship, but differ in shapes of the main piece, distal piece, and parameres (Figs. 69, 72). The metaventrite, antennal pocket, abdominal apex, and very complicated chaetotaxy of the protibiae are illustrated with SEMs (Figs. 310 – 313).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.63 / 0.63; head 0.25 / 0.35; pronotum 0.38 / 0.44, PA 0.39, PB 0.38; elytra 0.98 / 0.63. Dorsum dark brown to piceous; pronotum slightly lighter along anterior margin, legs and maxillary palpi dark brown to brown. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, some punctures on disc subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 11 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight or very slightly arcuate, distal 1 / 3 widened on anterior surface, moderately long spine on medial surface at base of widened area. Meso- and metatibia straight. Meso- and metatarsi with long hair-like setae along ventral margin. Fifth abdominal ventrite posteriorly very slightly transversely raised. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 72).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	etymology	Etymology. " Tricky legs "; named in reference to the similarity of the male legs to other Tetana group members that have long hair-like setae on the meso- and metatarsi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B57FFA0FF79F170FE19FDF6.taxon	distribution	Distribution. Currently known from Areas 1, 5, and 6, with only one or two localities in each; elevation range 1000 – 1891 m (Fig. 460).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	description	(Figs. 71, 73, 467)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Kewensa, Finisterre Range, Yupna, Huon Peninsula, stream margin, [GE est.] 100 – 500 m, 5 ° 49 ' S, 146 ° 46 ' E, 1 – 30 vii 1975, R. W. Hornabrook (NMNZ). Paratypes: Same data as holotype (12 NMNZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	diagnosis	Differential Diagnosis. Similar to H. tarsotricha in habitus and male sexual dimorphisms (no tubercle on first abdominal ventrite, fifth ventrite with transverse ridge, meso- and metatarsi with long hair-like setae) (Figs. 67, 71); differing therefrom by the narrower mesoventral intercoxal process P 2 (ratios ca 2 / 4 / 13 / 1 vs. 3 / 4 / 13 / 1). The male genitalia are also quite similar, differing most notably in the shapes of the parameres, and in details of the distal piece; reliable determinations will require examination of the aedeagi (Figs. 69, 73).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.73 / 0.70; head 0.28 / 0.40; pronotum 0.41 / 0.49, PA 0.43, PB 0.43; elytra 1.07 / 0.70. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 – 1.5 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 4 / 13 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 1, sides converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised, slightly slanting toward midline. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight or very slightly arcuate, distal 1 / 3 widened on anterior surface, cluster of short spines on medial surface at apex, moderately long spine on medial surface at base of widened area. Mesotibia very slightly arcuate. Metatibia straight, medial margin in distal 1 / 2 very slightly emarginate. Meso- and metatarsi with long hair-like setae along lower margin of basal tarsomeres. Fifth abdominal ventrite posteriorly transversely raised. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 73).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	etymology	Etymology. Named in reference to the Huon Peninsula.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B56FFA0FF79F099FE4CF84D.taxon	distribution	Distribution. Currently known only from the type locality on the Huon Peninsula (Area 5); elevation estimated at 100 – 500 m (Fig. 467).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	description	(Figs. 74, 76, 462)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Headwaters of Fio River, 0.5 km downstream of river crossing on Herowana / Oke Lookout path, ca. 4.5 km N of Herowana airstrip, washed from margins of riverside still water pools in rainforest; gravel and cobble dominated microhabitats, but some muddy, 1500 m, 6 ° 35 ' S, 145 ° 11 ' E, 29 v 2004, N. Porch (ANIC). Paratypes: Same data as holotype (25 ANIC).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	diagnosis	Differential Diagnosis. Similar to H. aulaarta in habitus and some male sexual dimorphisms (tubercle on first abdominal ventrite (Figs. 74, 82); differentiated therefrom by the larger size (ca. 1.81 vs. 1.64 mm), the slanting plaques, and, in males, the differently shaped pro- and metatibiae, and the meso- and metatarsi without long hairlike setae. Some of these differences are subtle; reliable determinations of the two species will require examination of the aedeagi, which distinctively differ (Figs. 76, 84).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.81 / 0.69; head 0.31 / 0.37; pronotum 0.41 / 0.48, PA 0.43, PB 0.39; elytra 1.06 / 0.69. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 6 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, some punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 13 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised, slightly more so laterally than medially. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight or very slightly arcuate, distal 1 / 4 widened on anterior surface, with cluster of short spines medially, moderately long spine on medial surface at base of widened area. Meso- and metatibia straight. First abdominal ventrite with large, sharply pointed tubercle in midline. Fifth abdominal ventrite simple. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 76).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	etymology	Etymology. " Without sandals "; named in reference to the lack of a large brush of setae on the tarsi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA7FF79F2BAFAAFFA0C.taxon	distribution	Distribution. Currently known only from the type locality in eastern Area 1, at 1500 m (Fig. 462).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	description	(Figs. 75, 77, 284, 285, 397, 468)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, ex stones and gravel bank of large river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 124) (NHM). Paratypes: Same data as holotype (11 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	diagnosis	Differential Diagnosis. Among members of the Tetana group, somewhat similar in habitus to H. insandalia and H. penultimata (Figs. 74, 75, 78); differing from both compared species by the shape of the pronotum, which is more widely produced in the middle, and nearly equally sinuate in front of and behind the widest part. Additionally, the males of H. biundulata have tibiae that are shaped differently than the compared species. The male genitalia of the three species are quite distinct, with H. biundulata being more similar to H. insandalia than to H. penultimata (Figs. 76, 77, 80). The metaventrite and the chaetotaxy of the meso- and metatibiae are illustrated with SEMs (Figs. 284, 285).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.55 / 0.63; head 0.26 / 0.37; pronotum 0.40 / 0.48, PA 0.40, PB 0.38; elytra 0.90 / 0.63. Dorsum of head piceous; pronotum light brown in front of and behind piceous, diffusely margined, fascia, ratios of color bands, as measured in midline, ca. 6 / 15 / 5; elytra dark brown; legs and maxillary palpi dark brown. Dorsum moderately shining. Frons punctures ca. 2 xef near eyes, smaller and sparser medially; interstices shining, medially 3 – 7 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum microreticulate in shallow median depression, otherwise moderately coarsely punctate. Genae very slightly raised, shining, with shallow, obsolete anteromedian impression, without posterior ridge. Pronotum subcordiform, distinctively narrowed both in front of and behind widest area; median 2 / 3 of anterior margin emarginate; punctures on disc slightly smaller than largest frons punctures, interstices shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly ca. 2 xpd those on disc, and denser; PF 1 absent; PF 2 and PF 4 very shallow; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity slightly posterior to midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 9 / 4. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 3, transversely very slightly concave, sides very slightly diverging toward blunt apex. Plaques large, raised slightly more laterally than medially, at sloping sides of median depression, anteriorly slightly tapering and convergent; each plaque with tiny papilla slightly behind midlength. Metaventrite between mesocoxae very weakly raised in midline. AIS width at straight posterior margin ca. 1.5 x P 2. All legs rather long and slender. Profemur (male) with tubercle on ventral margin near trochanter; protibia arcuate, increasing in width from near base to subapically. Mesotibia slightly arcuate. Metatibia sinuate, slender except apically widened and bearing few setae. Abdominal apex very slightly asymmetrical, if at all; last tergite (male) with very small apicomedian notch. Aedeagus as illustrated (Fig. 77). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 397).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	etymology	Etymology. Named in reference to the undulating medial surface of the male metatibiae and undulating margin of the pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B51FFA6FF79F7CBFC8CFB36.taxon	distribution	Distribution. Currently known only from the type locality on the Lae – Bulolo road, at the eastern end of Area 3 where it borders Area 6; elevation 900 – 1100 m (Fig. 468).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	description	(Figs. 78, 80, 465)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: May River, ex river side pool, 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (ZSM). Paratype: Same data as holotype (1 male ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	diagnosis	Differential Diagnosis. Immediately differentiated from other members of the Tetana group by the elongate, fasciate pronotum (PL / PW ca. 0.94 vs. 0.83 – 0.87 for other species). The metaventral plaques are narrower and more widely separated than other members of the group, except H. altapapua (Figs. 78, 83). Males are additionally recognized by the uniquely widened and flattened penultimate maxillary palpomere. The aedeagus of this species stands apart from that of other members of the Tetana group (Fig. 80). This species, from far western PNG (Fig. 465), might represent a species group of western NG.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.87 / 0.72; head 0.28 / 0.40; pronotum 0.47 / 0.50, PA 0.44, PB 0.42; elytra 1.11 / 0.72. Dorsum of head piceous; pronotum with very large piceous fascia, bordered anteriorly and posteriorly by light brown to testaceous, color band ratios ca. 7 / 20 / 3, posterior band very faint; legs and maxillary palpi brown. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 2 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Maxillary palpus (male) with penultimate palpomere widened, ventral surface flat. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate medially, otherwise finely punctate and shining. Genae raised, shining, without posterior ridge. Pronotum moderately elongate, PL / PW ca. 0.94, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 13 / 2. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides converging toward blunt apex. Plaques very large, very narrowly separated, medial margins parallel, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight or very slightly arcuate, in ventral aspect gradually increasing in width from base to apex, distal 1 / 3 slightly widened on anterior surface, cluster of short spines apically on medial surface, moderately long spine on medial surface at base of widened area. Mesotibia very slightly arcuate; mesotarsi with short setae along lower margin. Metatibia straight, medial margin very weakly widened near midlength; metatarsi with long hair-like setae along lower margin of basal tarsomeres. Fifth abdominal ventrite simple. Sixth ventrite medial area flattened, on each side of which very slightly raised. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 80).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	etymology	Etymology. Named in reference to the male modified penultimate maxillary palpomere.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B50FFA5FF79F6C4FD8DFCAE.taxon	distribution	Distribution. Currently known only from the type locality, which is at the border of Areas 1 and 2 in far western PNG; elevation 970 m (Fig. 465).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	description	(Figs. 79, 81, 466)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Koma River, tributary of Fio River, 100 m downstream of rattan bridge crossing, ca. 3.8 km S by E of Herowana airstrip, washed from margins of small pool of a steep, rocky, forest stream at confluence with river; gravel, cobbles, wet rock microhabitats, 1100 m, 6 ° 40 ' S, 145 ° 12 ' E, 31 v 2004, N. Porch (ANIC). Paratypes (4): Eastern Highlands Province: Same data as holotype (1 ANIC); Crater Mt., trek Haia – Wara Sera, 500 m, 6 ° 38.517 ' S, 145 ° 6.097 ' E, 12 ix 2002, Balke & Sagata (PNG 7) (1 NHM, 2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	diagnosis	Differential Diagnosis. Similar to H. tetana in habitus, size, plaques, and some male sexual dimorphisms (tubercle on first abdominal ventrite, meso- and metatarsi with long hair-like setae (Figs. 66, 79); differing therefrom by slightly finer dorsal punctation and shape of the male protibial apex. Reliable determinations of the two species will require examination of the aedeagi, which distinctively differ (Figs. 68, 81).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.65 / 0.65; head 0.27 / 0.36; pronotum 0.39 / 0.46, PA 0.39, PB 0.37; elytra 0.98 / 0.65. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 6 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, some punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect separately rounded, in posterior aspect margins forming moderately deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 10 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter. Protibia appearing compressed at ca. distal 1 / 3, then markedly, roundly widened on anterior surface, widened area with row of short spines on medial low ridge, and cluster of spines apically; lateral surface slightly emarginate. Mesotibia very slightly arcuate. Metatibia straight. Meso- and metatarsi with long hair-like setae along lower margin of basal tarsomeres. First abdominal ventrite with sharp tubercle in midline. Fifth abdominal ventrite simple. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 81).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	etymology	Etymology. Named in reference to the sharply pointed process on the midline of the first abdominal ventrite of males.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B53FFA4FF79F1A1FCB6FE46.taxon	distribution	Distribution. Currently known from two very narrowly separated localities at the border of southeastern Area 1 and Area 13; elevation range 500 – 1100 m (Fig. 466).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	description	(Figs. 82, 84, 463)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	materials_examined	Type Material. Holotype (male): Western Highlands Province: Kundum, 1400 m, 5 ° 16.096 ' S, 144 ° 27.869 ' E, 3 iii 2007, Kinibel (PNG 142) (ZSM). Paratypes (19): Madang Province: Simbai area, 1200 m, 5 ° 13.389 ' S, 144 ° 37.285 ' E, 10 iii 2007, Kinibel (PNG 152) (2 ZSM); Sandaun Province: Dogman River, ex surface of rocks, 2054 m, 4 ° 55.789 ' S, 141 ° 38.202 ' E, 15 xi 2003, K. Sagata (WB 21) (1 ZSM); May River, ex river side pool, 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (1 ZSM); Western Highlands Province: Same data as holotype (13 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	diagnosis	Differential Diagnosis. Similar to H. insandalia in habitus and some male sexual dimorphisms (tubercle on first abdominal ventrite (Figs. 74, 82); differing therefrom by the smaller size (ca. 1.64 vs. 1.81 mm), the flat plaques, and, in males, the differently shaped pro- and metatibiae, and the meso- and metatarsi with long hair-like setae. Some of these differences are subtle; reliable determinations of the two species will require examination of the aedeagi, which distinctively differ (Figs. 76, 84).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.64 / 0.68; head 0.25 / 0.39; pronotum 0.40 / 0.48, PA 0.42, PB 0.39; elytra 1.01 / 0.68. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 6 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull, except anterior margin shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 6 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 12 / 1. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward blunt apex. Plaques very large, very narrowly separated, slightly more narrowly separated posteriorly than anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter. Protibia appearing compressed at ca. distal 1 / 3, then roundly widened on anterior surface, moderately long spine on medial surface at base of widened area. Mesotibia very slightly arcuate, medial margin slightly flattened. Metatibia very slightly arcuate. Meso- and metatarsi with moderately long setae along lower margin that lie flat on cuticle. Fifth abdominal ventrite simple. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 84).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	etymology	Etymology. " Furrow narrow "; named in reference to the narrowly separated metaventral plaques.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B52FFA4FF79F009FC01F804.taxon	distribution	Distribution. Currently known from Area 1, near the northern margin; elevation range 970 – 2054 m, with the only record below 1200 m being 970 m at the Mianmin area (Fig. 463).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	description	(Figs. 83, 85, 464)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	materials_examined	Type Material. Holotype (male): Southern Highlands Province: Sopulkul, 30 – 35 km NE Mendi, 2680 m, 6 ° 2.944 ' S, 143 ° 46.485 ' E, 16 vi 2006, John (PNG 79) (ZSM). Paratypes (32): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 2400 m, 5 ° 55.615 ' S, 145 ° 22.699 ' E, 23 xi 2006, Balke & Kinibel (PNG 107) (3 ZSM); Akameku – Brahmin, Bismarck Range ,, 2200 m, 5 ° 56.801 ' S, 145 ° 22.238 ' E, 23 xi 2006, Balke & Kinibel (PNG 106) (4 ZSM); Madang Province: Sepik-Ramu Basin, Cold Creek, montane stream tumbled down among moss-covered rocks which alternated with short sandy runs in more level sections, almost completely shaded, [GE est.] 2000 – 2200 m, 5 ° 45 ' S, 145 ° 8 ' E, 7 vi 1988, D. Dudgeon (2 NMW); Southern Highlands Province: Same data as holotype (23 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Tetana group by the large size (ca. 2.03 mm), the comparatively deep pronotal foveae PF 2, the convex elytra, and the comparatively small (for this group) and widely spaced metaventral plaques that are more widely spaced posteriorly than anteriorly (Fig. 83). The male genitalia distinctly differ from that of other members of the Tetana group (Fig. 85).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.03 / 0.83; head 0.31 / 0.44; pronotum 0.48 / 0.58, PA 0.48, PB 0.50; elytra 1.25 / 0.83. Dorsum piceous; legs and maxillary palpi dark brown. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd, anterolateral angles microreticulate. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum densely micropunctulate, dull. Genae raised, shining, without posterior ridge, posteromedially with small pit into which apicomedian process of prosternum fits when head retracted. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 extremely shallow or absent; PF 2 moderately deep, posterior margins obsolete, shallowly confluent; PF 3 deep; PF 4 absent. Elytra transversely convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 3 / 10 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly diverging toward blunt apex. Plaques moderately large, converging anteriorly, twice as widely separated posteriorly as anteriorly, weakly raised. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin very slightly wider than P 2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, distal 1 / 3 weakly widened on anterior surface, moderately long spine on medial surface at ca. distal 1 / 3. Meso- and metatibia straight. Meso- and metatarsi with short setae along lower margin. Fifth abdominal ventrite simple. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 85).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	etymology	Etymology. Named in reference to the high elevation at which this species lives; the 2680 m locality record is the highest known for PNG Hydraena.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5DFFABFF79F2BAFB50F9BC.taxon	distribution	Distribution. Currently known from eastern Area 1; elevation range 2200 – 2680 m (Fig. 464).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	description	(Figs. 86, 88, 469)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Koma River, tributary of Fio River, 100 m downstream of rattan bridge crossing, ca. 3.8 km S by E of Herowana airstrip, washed from margins of small pool of a steep, rocky, forest stream at confluence with river; gravel, cobbles, wet rock microhabitats, 1100 m, 6 ° 40 ' S, 145 ° 12 ' E, 31 v 2004, N. Porch (ANIC).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	diagnosis	Differential Diagnosis. Somewhat similar in habitus to H. biundulata (Tetana group), including the shape of the sides of the pronotum, which are nearly equally sinuate in front of and behind the widest part (Figs. 75, 86); distinguished therefrom by the markedly arcuate anterior margin of the pronotum, the very different metaventral plaques, and the different elytral coloration. Additionally, males have very differently shaped tibiae in the two species. The male genitalia of the two species differ greatly (Figs. 77, 88).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.64 / 0.63; head 0.29 / 0.36; pronotum 0.38 / 0.45, PA 0.38, PB 0.36; elytra 0.96 / 0.63. Dorsum of head with frons and clypeus piceous; labrum dark brown; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 15 / 5; elytra dark brown to piceous in ca. anterior 2 / 5 and narrowly along explanate margin, otherwise elytra light brown to testaceous; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately strongly shining. Frons punctures ca. 1 xef, only slightly larger near eyes, sparser medially; interstices shining, medially 2 – 5 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum and postmentum conjointly weakly concave. Mentum effacedly microreticulate, very sparsely very finely punctulate, weakly shining. Postmentum microreticulate, dull. Genae very slightly raised, weakly shining, with small median impression, without posterior ridge. Pronotum subcordiform, distinctively narrowed both in front of and behind widest area; ca. median 1 / 2 of anterior margin rather markedly arcuate to posterior; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly ca. 2 xpd those on disc, and denser; PF 1 and PF 4 absent; PF 2 very shallow, obsolete; PF 3 deep, wide. Elytra widest at about midlength; summit of posterior declivity at about midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices partly missing in holotype. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 6 / 5. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 3, sides very slightly diverging toward blunt apex. Plaques carinate lines, gradually raising from anterior to posterior, at sides of median depression, anteriorly slightly convergent. Metaventrite flat or slightly concave between mesocoxae. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length. Profemur (male) with minute tubercle on ventral margin near trochanter; protibia straight, medial margin widened from about midlength to subapically, then narrowed to apex, greatest width ca. 1.5 x width at midlength. Mesotibia straight, slender, with many short spine-like setae. Metatibia with medial margin distinctly widened at about midlength, greatest width ca. 1.5 x width at apex; lateral margin emarginate. Abdominal apex symmetrical; last tergite (male) with large, deep apicomedian notch. Aedeagus as illustrated (Fig. 88).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	etymology	Etymology. Named in reference to the Koma River.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5CFFAAFF79F2BAFD5AF900.taxon	distribution	Distribution. Currently known only from the type locality, the Koma River in southeastern Area 1, near where Area 1 borders Area 13; elevation 1100 m (Fig. 469).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	description	(Figs. 87, 89, 316 – 318, 398, 471)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: 5 miles W of Lae, Buins Creek, ex sand and gravel banks of clear fast river, [GE est.] 10 – 40 m, 6 ° 43 ' S, 147 ° 2 ' E, 28 xii 1965, M. E. Bacchus (MEB 121) (NHM). Paratypes (30): Madang Province: 5 km NW CRI, Nagada Harb, [GE est.] 10 – 30 m, 5 ° 20 ' S, 145 ° 42 ' E, 18 iii 1991, D. Larson (2 MCZ); Gogal Valley, 4 km S Baru Village, [GE est.] 300 – 500 m, 5 ° 42 ' S, 146 ° 32 ' E, 10 iv 1991, D. Larson (2 MCZ); Ramu Valley, 2 km SE Brahman, [GE est.] 130 – 150 m, 5 ° 43 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (1 MCZ); Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (1 NMW); Morobe Province: Same data as holotype (9 NHM); Herzog Mts., Bundun, 700 – 800 m, 6 ° 51.598 ' S, 146 ° 37.07 ' E, 2 iv 2006, Balke & Sagata (PNG 27) (6 MCZ, NHM, NMW, PNG, ZSM); Herzog Mts., Bundun, beating leaves, 700 – 800 m, 6 ° 51.598 ' S, 146 ° 37.07 ' E, 2 iv 2006, Balke & Sagata (PNG 28) (2 ZSM); Sandaun Province: road Vanimo – Bewani close coast, 400 – 480 m, 2 ° 44.372 ' S, 141 ° 15.067 ' E, 13 iv 2006, Balke & Sagata (PNG 41) (2 ZSM); Western Highlands Province: Sepik River Basin, Kil Stream, montane forest, 1800 m, 5 ° 40 ' S, 144 ° 42 ' E, 16 viii 1988, D. Dudgeon (5 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	diagnosis	Differential Diagnosis. Among members of the Colorata group similar to H. nanocolorata in having shallow pronotal foveae PF 2 and a distinctive pronotal fascia (Figs. 87, 98); distinguished therefrom by the larger size (ca. 1.25 vs. 1.15 mm), the differently shaped pronotum (PA and PB equal), the proportionally longer elytra, and the slightly denser dorsal punctation. The pronotal fasciae also differ in the two species, the color band ratios being ca. 7 / 10 / 5 in H. colorata and ca. 6 / 9 / 4 in H. nanocolorata. The male genitalia of the two species distinctively differ (Figs. 89, 100). The metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 316 – 318).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.25 / 0.54; head 0.19 / 0.29; pronotum 0.31 / 0.39, PA 0.33, PB 0.33; elytra 0.77 / 0.54. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 7 / 10 / 5; elytra brown; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices weakly shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and anterior 2 / 3 of postmentum very sparsely and very finely punctulate, strongly shining; posterior 1 / 3 of postmentum with much larger punctures. Genae raised, shining, without posterior ridge. Pronotum weakly cordiform, anterior margin emarginate; punctures on disc ca. 1 xpd of largest frons punctures, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 united to form very shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 shallow, oval, oblique, very shallowly confluent; PF 3 moderately deep; PF 4 obsolete. Elytra with summit of posterior declivity slightly before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures slightly larger than largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 4 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques short, carinate, located at sides of deep, inverted V-shaped median depression. Metaventrite with very low midlongitudinal ridge between P 2 and apex of median depression. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly thickened in distal 1 / 2. Mesotibia straight. Metatibia straight, medial margin in distal 1 / 3 with few recumbent hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 89). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 398).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	etymology	Etymology. Named in reference to the dorsal coloration.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5FFFA8FF79F0FAFD3DFDF6.taxon	distribution	Distribution. Currently known from Areas 2 – 6, at an elevation range of 10 – 800 m, and one perhaps questionable locality in Area 1, at 1800 m (Fig. 471).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	description	(Figs. 90, 92, 474)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of swift shallow clear river, 1128 m, 6 ° 48 ' S, 146 ° 48 ' E, 8 i 1965, M. E. Bacchus (MEB 145 a) (NHM). Paratypes (20): Morobe Province: Same data as holotype (11 NHM); Herzog Mts., Vagau [Wagau], ex muddy gravel banks of shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 b) (7 NHM); Herzog Mts., Vagau [Wagau], Snake River, under gravel in bed of large slow river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 15 i 1965, M. E. Bacchus (MEB 152) (1 NHM); Markham Valley, Gusap, c. 90 mi. W of Lae, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 166) (1 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	diagnosis	Differential Diagnosis. Among members of the Colorata group, similar to H. paxillipes in having deep pronotal foveae PF 2 and a very distinctive pronotal fascia (Figs. 90, 91); distinguished therefrom by the slightly larger size (ca. 1.55 vs. 1.47 mm), the more elongate pronotum (PL / PW ca. 0.86 vs. 0.77), and the slightly different plaque configurations. Males are additionally differentiated by the more markedly modified protibiae of H. fasciata, and the more distinctly arcuate metatibiae of H. paxillipes. The male genitalia of the two species markedly differ (Figs. 92, 93).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.55 / 0.64; head 0.24 / 0.36; pronotum 0.38 / 0.44, PA 0.37, PB 0.37; elytra 0.97 / 0.64. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 8 / 12 / 5; elytra brown, very slightly lighter around summit of posterior declivity; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely and very finely punctulate, strongly shining, each puncture with very fine, recumbent seta. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin straight; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 deep, oval, oblique, shallowly confluent; PF 3 moderately deep; PF 4 shallow. Elytra with summit of posterior declivity slightly before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 5 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex, apex joined to mesoventral midlongitudinal ridge. Plaques carinate, located at sides of deep, inverted V-shaped median depression. Metaventrite with midlongitudinal ridge between mesoventral intercoxal process and apex of median depression. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. All legs long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia distinctively modified, median 1 / 3 of medial margin widened and bearing row of short stout spines, margin between apex and spines slightly emarginate. Mesotibia straight. Metatibia very slender, very slightly emarginate on medial surface. Abdominal apex symmetrical, or nearly so; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 92).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	etymology	Etymology. Named in reference to the fasciate pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5EFFAFFF79F099FD88FED6.taxon	distribution	Distribution. Currently known from the Markham Valley at the border of Areas 3 and 5 (305 m), and the Herzog Mts., Area 6 (1220 m) (Fig. 474).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	description	(Figs. 91, 93, 319 – 321, 472)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (NHM). Paratypes (52): Madang Province: Akameku – Brahmin, Bismarck Range, 750 m, 5 ° 49.307 ' S, 145 ° 24.389 ' E, 25 xi 2006, Balke & Kinibel (PNG 114) (1 ZSM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (10 NHM); Ramu Valley, Sare River, 4 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 16 iv 1991, D. Larson (10 MCZ); Morobe Province: Lae – Bulolo road, ex muddy gravel bank of small shaded stream, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 125) (16 NHM); Lae – Bulolo road, Gurakor Creek, ex gravel banks, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 133) (5 NHM); Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (4 NHM); Lae, Umg. [= environs of] Oomsis, Buang River, [GE est.] 20 – 30 m, 6 ° 53 ' S, 146 ° 57 ' E, 14 vi 1979, W. G. Ullrich (1 NHM); Sandaun Province: Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (1 ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (4 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	diagnosis	Differential Diagnosis. Among members of the Colorata group similar to H. fasciata and H. diadema in having deep pronotal foveae PF 2 and a very distinctive pronotal fascia (Figs. 90, 91, 94); distinguished from H. fasciata by the slightly smaller size (ca. 1.47 vs. 1.55 mm), the more transverse pronotum (PL / PW ca. 0.77 vs. 0.86), and the slightly different plaque configurations; differentiated from H. diadema by the shorter and more widely spread plaques and the narrower elytra. Males are additionally differentiated by the more markedly modified protibiae of H. fasciata, and the more distinctly arcuate metatibiae of H. paxillipes. The male genitalia of the three species markedly differ (Figs. 92, 93, 96). The metaventrite and the complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 319 – 321).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.47 / 0.63; head 0.22 / 0.33; pronotum 0.33 / 0.43, PA 0.37, PB 0.37; elytra 0.90 / 0.63. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 7 / 11 / 5; elytra brown, with lighter, diffusely margined macula around summit of posterior declivity; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely and very finely punctulate, strongly shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin very slightly emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 deep, oval, oblique, shallowly confluent; PF 3 moderately deep; PF 4 shallow. Elytra with summit of posterior declivity slightly before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming moderate angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 4 / 5. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques short, carinate, located at sides of deep, inverted V-shaped median depression. Metaventrite with very short midlongitudinal ridge anterior to apex of median depression, ridge not attaining mesoventral intercoxal process. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly thickened, medial margin bearing row of short stout peg-like spines. Mesotibia straight. Metatibia very slender, moderately arcuate, slightly thickened in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 93).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	etymology	Etymology. " Peg leg "; named in reference to the row of peg-shaped spines on the male protibiae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B59FFAEFF79F3B9FB74FED6.taxon	distribution	Distribution. Currently known from Areas 2 and 3; elevation range 20 – 1100 m (Fig. 472).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	description	(Figs. 94, 96, 443)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (NHM). Paratypes: Morobe Province: Lae – Bulolo road, Patep Creek, ex gravel bank of large fast river, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 126) (4 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	diagnosis	Differential Diagnosis. Among members of the Colorata group similar to H. fasciata and H. paxillipes in having deep pronotal foveae PF 2 and a very distinctive pronotal fascia (Figs. 90, 91, 94); distinguished from both species by the more ovoid elytra, the proportionally larger pronotal fascia, and the different plaque ratios. The male genitalia of the three species markedly differ (Figs. 92, 93, 96).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.47 / 0.65; head 0.22 / 0.34; pronotum 0.36 / 0.43, PA 0.37, PB 0.36; elytra 0.88 / 0.65. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 13 / 5; elytra dark brown; legs light brown; maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin straight; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow; PF 2 moderately deep; PF 3 deep; PF 4 shallow. Elytra very convex, widest slightly past midlength, apically broadly rounded; posterior declivity very steep, summit before midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly broadly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 6 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised in form of low keel, l / w ca. 2 / 1. Plaques very narrow, carinate, especially posteriorly, parallel, located at sides of deep, median depression. Metaventrite anteriorly with low midlongitudinal ridge. AIS at least partially fused with first abdominal ventrite, width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, slightly wider subapically than apically. Mesotibia straight. Metatibia slightly arcuate. Abdominal apex symmetrical; last tergite (male) notched.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	etymology	Etymology. " Headband "; named in reference to the testaceous band above the eyes, on the pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFAEFF79F3B9FD4AF9E5.taxon	distribution	Distribution. Currently known from two localities, one in eastern Area 1 at 1500 – 1700 m, and one that is at the border of Areas 3 and 6, at 900 – 1100 m (Fig. 443).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	description	(Figs. 95, 97, 399, 473)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: c. 7 miles Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (NHM). Paratypes (116): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (88 NMW); Morobe Province: 3 miles Bulolo – Lae road, ex mud banks of small stream, [GE est.] 50 – 150 m, 6 ° 42 ' S, 146 ° 57 ' E, 29 xii 1964, M. E. Bacchus (MEB 128) (2 NHM); Kassam Pass, Yung Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 0 ' E, 8 v 1979, W. G. Ullrich (4 MHNG); Lae – Bulolo road, ex dead leaves on mud bank, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 123) (21 NHM); Western Highlands Province: Sepik River Basin, Kil Stream, montane forest, 1800 m, 5 ° 40 ' S, 144 ° 42 ' E, 16 viii 1988, D. Dudgeon (1 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	diagnosis	Differential Diagnosis. Distinguished from other members of the Colorata group by the pronotal macula, which grades to lighter color laterally but does not form a fascia; the color band ratios also differ from other species in the group, being ca. 4 / 4 / 3. Males have the protibiae and metatibiae modified somewhat similar to those of H. paxillipes, but the habitus and male genitalia of the two species differ markedly (Figs. 91, 93, 95, 97).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.58; head 0.20 / 0.31; pronotum 0.33 / 0.41, PA 0.34, PB 0.34; elytra 0.80 / 0.58. Dorsum of head piceous; pronotum testaceous in front of and behind dark brown to piceous macula that gradually grades to light brown laterally, hence sub-fasciate, ratios of color bands, as measured in midline, ca. 8 / 8 / 6; elytra dark brown, very slightly lighter around summit of posterior declivity; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely and very finely punctulate, strongly shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin very slightly emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 shallow, oval, oblique, shallowly confluent; PF 3 moderately deep; PF 4 shallow or obsolete. Elytra with summit of posterior declivity slightly before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, effacedly microreticulate, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 4 / 4. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques short, carinate, located at sides of deep, inverted V-shaped median depression. Metaventrite with very low midlongitudinal ridge between P 2 and apex of median depression. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, medial margin in distal 1 / 2 distinctively thickened and bearing row of very short, peg-like spines. Mesotibia straight. Metatibia moderately arcuate, medial margin in distal 1 / 4 with few recumbent hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 97). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 399).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	etymology	Etymology. Named in reference to the wide elevation range of the known collection localities.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B58FFADFF79F4EBFEB8FA0A.taxon	distribution	Distribution. Currently known from the eastern parts of Areas 1 – 3; with a wide elevation range, 10 – 1800 m (Fig. 473).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	description	(Figs. 98, 100, 475)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes (101): Madang Province: Same data as holotype (84 NMW); Morobe Province: Markham Valley, Gusap, 90 miles NW of Lae, ex dead leaves on mud wetted by seepage, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 163) (17 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	diagnosis	Differential Diagnosis. Among members of the Colorata group similar to H. colorata in having shallow pronotal foveae PF 2 and a distinctive pronotal fascia (Figs. 87, 98); distinguished therefrom by the smaller size (ca. 1.15 vs. 1.25 mm), the differently shaped pronotum (PA slightly greater than PB), the proportionally shorter elytra, and the slightly sparser dorsal punctation. The pronotal fasciae also differ in the two species, the color band ratios being ca. 6 / 9 / 4 in H. nanocolorata and ca. 7 / 10 / 5 in H. colorata. The male genitalia of the two species distinctively differ (Figs. 89, 100).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.15 / 0.52; head 0.17 / 0.29; pronotum 0.30 / 0.39, PA 0.33, PB 0.32; elytra 0.69 / 0.52. Dorsum of head piceous; pronotum testaceous to light brown in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 9 / 4; elytra brown; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 2 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely and very finely punctulate, strongly shining. Genae very slightly raised, shining, without posterior ridge. Pronotum cordiform, anterior margin emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 united to form shallow transverse impression across anterior 1 / 3 of pronotal disc; PF 2 shallow, oval, oblique, shallowly confluent; PF 3 moderately deep; PF 4 shallow. Elytra weakly convex, posterior declivity gradual, summit of posterior declivity slightly before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 4 / 4. P 1 laminate; median carina sinuate in profile. P 2 very slightly raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques short, carinate, located at sides of deep, inverted U-shaped median depression. Metaventrite with very low midlongitudinal ridge between P 2 and apex of median depression. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, pointed tubercle next to trochanter; protibia slightly arcuate, medial margin in distal 1 / 2 distinctively thickened and bearing row of very short, peg-like spines. Mesotibia straight. Metatibia straight, medial margin in distal 1 / 4 with few recumbent hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 100).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	etymology	Etymology. Named in reference to the small size and relationship with H. colorata.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5BFFACFF79F7C8FA39FB99.taxon	distribution	Distribution. Currently known from two localities in eastern Area 3; elevations 160 m and 305 m (Fig. 475).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	description	(Figs. 99, 101, 476)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes: Same data as holotype (8 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Colorata group by the small size (ca. 1.13 mm) and the clear pronotum, which does not have a macula or fascia (Fig. 99). The testaceous pronotum is similar in color to that of H. ramuensis (which see), but otherwise the two species differ distinctively. The male genitalia bear some superficial similarity to that of H. colorata, but the two distinctively differ in many details (Figs. 89, 101).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.13 / 0.50; head 0.18 / 0.28; pronotum 0.29 / 0.36, PA 0.31, PB 0.32; elytra 0.67 / 0.50. Dorsum of head dark brown; pronotum testaceous to light brown, no macula or fascia; elytra brown; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 2 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely and very finely punctulate, strongly shining. Genae very slightly raised, shining, without posterior ridge. Pronotum weakly cordiform, anterior margin slightly emarginate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, almost obsolete; PF 2 very shallow, oval, oblique, very shallowly confluent; PF 3 moderately deep; PF 4 absent. Elytra with summit of posterior declivity before midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 3 / 3. P 1 laminate; median carina sinuate in profile. P 2 very slightly raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques short, carinate, located at sides of deep, inverted V-shaped median depression. Metaventrite with very low midlongitudinal ridge between P 2 and apex of median depression. AIS slightly concave, width at straight posterior margin ca. 1.5 x P 2. Profemur (male) with small, pointed tubercle next to trochanter; protibia slightly arcuate, medial margin in distal 1 / 2 slightly thickened and bearing row of very short, peg-like spines. Mesotibia straight. Metatibia very slightly, if at all, arcuate. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 101).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	etymology	Etymology. Named in reference to the clear and bright pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B5AFFD3FF79F649FF64FE62.taxon	distribution	Distribution. Currently known only from type locality, Kojé Creek in eastern Area 3; elevation 160 m (Fig. 476).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	description	(Figs. 102, 104, 477)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, 6 km N Brahman, [GE est.] 130 – 150 m, 5 ° 38 ' S, 145 ° 22 ' E, 21 vi 1991, D. Larson (MCZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	diagnosis	Differential Diagnosis. Similar to H. clarinis (Colorata group) in having a completely testaceous pronotum (Figs. 99, 230); differentiated therefrom by the larger size (ca. 1.22 vs. 1.13 mm), the much more convex and ovate elytra that have a testaceous macula, and the more coarsely punctate dorsum. The male genitalia of the two species distinctively differ (Figs. 101, 104).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.22 / 0.54; head 0.16 / 0.30; pronotum 0.30 / 0.38, PA 0.30, PB 0.33; elytra 0.76 / 0.54. Dorsum of head dark brown to piceous; pronotum testaceous; elytra dark brown with light brown to testaceous macula across middle area, and similarly colored elytral apices; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 2 xef near eyes, smaller and sparser medially; interstices shining, medially 1 – 3 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae very slightly raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; sides straight between anterior angle and widest part, sinuate between widest part and posterior angle; punctures on disc ca. 2 xpd largest frons punctures, interstices shining, ca. 1 – 2 xpd, punctures anteriorly and posteriorly slightly larger and denser than those on disc; PF 1 and PF 4 very shallow or absent; PF 2 shallow, obsolete; PF 3 moderately deep, wide. Elytra ovoid, transversely very convex, widest at about midlength; summit of posterior declivity distinctly anterior to midlength, at ca. anterior margin of macula; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very slightly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 5 / 4. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 2, sides very slightly converging toward blunt, slightly raised apex. Plaques very narrow but not carinate, at sides of median depression, anteriorly tapering, parallel or very slightly convergent. Metaventrite transversely slightly concave between mesocoxae, tip raised to join with tip of P 2. AIS width at straight posterior margin ca. 2 x P 2. All legs of moderate length. Profemur (male) with tubercle on ventral margin near trochanter; protibia slightly arcuate, slightly widened in distal 1 / 2. Meso- and metatibia straight, slender. Metatrochanter with minute tubercle. Abdominal symmetrical; last tergite (male) with deep apicomedian notch. Aedeagus as illustrated (Fig. 104).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	etymology	Etymology. Named in reference to the Ramu Valley.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B25FFD2FF79F183FA20FEA9.taxon	distribution	Distribution. Currently known only from the type locality in eastern Area 3; elevation 130 – 300 m (Fig. 477).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	description	(Figs. 103, 105, 478)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Akameku – Brahmin, Bismarck Range, 250 – 500 m, 5 ° 47.026 ' S, 145 ° 24.131 ' E, 25 xi 2006, Balke & Kinibel (PNG 115) (ZSM). Paratypes (2): Madang Province: Same data as holotype (1 ZSM); near Brahmin, 200 m, 5 ° 47.026 ' S, 145 ° 24.131 ' E, 25 xi 2006, Balke & Kinibel (PNG 116) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	diagnosis	Differential Diagnosis. The pronotal shape and impressions are somewhat similar to those of H. velvetina (Velvetina group) and H. fasciata (Colorata group) (Figs. 90, 103, 106). However, the overall body shape, metaventral plaque ratios, and legs of males differ from those of the compared groups. The aedeagus of H. cunicula (Fig. 105) also indicates that placement should not be with those groups.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.59; head 0.21 / 0.33; pronotum 0.32 / 0.44, PA 0.36, PB 0.35; elytra 0.79 / 0.59. Dorsum of head dark brown to piceous; labrum testaceous; pronotum light brown to testaceous in front of and behind brown to dark brown fascia, ratios of color bands, as measured in midline, ca. 6 / 11 / 4; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 – 2 xef near eyes, smaller and sparser medially; interstices shining, medially 1 – 3 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum effacedly microreticulate in posterior 1 / 2, otherwise finely sparsely punctulate. Genae very slightly raised, shining, without posterior ridge, but lateral impressions wide. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; sides straight or very slightly emarginate between anterior angle and widest part, sinuate between widest part and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 1 – 3 xpd, punctures anteriorly and posteriorly denser than those on disc; PF 1 and PF 4 very shallow; PF 2 moderately deep, medially conjointly shallowly confluent; PF 3 moderately deep, wide. Elytra transversely convex, widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, very weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 5 / 4. P 1 slightly wider than laminate; median carina sinuate in profile, slightly raised between coxae. P 2 wide, length / width ca. 5 / 4, sides very slightly diverging toward blunt apex. Plaques very narrow, raised but not carinate, at sides of deep median inverted V-shaped depression, anteriorly slightly convergent. Metaventrite slightly concave between mesocoxae. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length, slender. Profemur (male) with minute tubercle on ventral margin near trochanter; protibia slightly arcuate, gradually increasing in width from base to apex. Meso- and metatibia straight, slender. Metatibia widest, but extremely slightly so, near midlength. Abdominal apex symmetrical; last tergite (male) with deep apicomedian notch. Aedeagus as illustrated (Fig. 105).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	etymology	Etymology. " Little rabbit "; named in reference to the rabbit ear shape of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B24FFD1FF79F133FE22FE11.taxon	distribution	Distribution. Currently known only from two very closely spaced localities in eastern Area 3; elevation range 200 – 500 m (Fig. 478).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	description	(Figs. 106, 108, 479)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (NHM). Paratypes (13): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (10 NHM); Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 140 a) (1 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (2 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	diagnosis	Differential Diagnosis. Immediately differentiated from other members of the Velvetina group by the dorsal color, the comparatively wide pronotum having a piceous fascia bordered by testaceous bands in front and back (color band ratios ca. 5 / 15 / 4) (Fig. 106). In addition, the elytra, when viewed posteriorly, do not form an angle with one another. The aedeagus of H. velvetina is perhaps best compared with that of H. bubulla (Figs. 108, 113), but the two differ markedly in many ways, and externally the two species are quite distinct (Figs. 106, 111).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.50 / 0.60; head 0.24 / 0.33; pronotum 0.36 / 0.43, PA 0.36, PB 0.34; elytra 0.90 / 0.60. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5 / 15 / 4; elytra brown; legs light brown to testaceous; maxillary palpi testaceous. Frons punctures ca. 1 xef; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum slightly concave, very sparsely very finely punctulate, strongly shining; postmentum effacedly micropunctulate in median concavity. Genae raised, shining, with tiny median pit-like fovea, without posterior ridge. Pronotum cordiform, anterior margin straight or slightly arcuate; punctures on disc ca. 1 xpd those of frons, interstices shining, 1 – 2 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 shallow; PF 2 deep, large, oval, oblique, very shallowly confluent, together forming U-shaped impression; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins do not form angle with one another. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques absent, hydrofuge pubescence longest on raised sides of large, deep median depression. AIS width at straight posterior margin ca. 2 x P 2. All legs long and moderately slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to about midlength, then emarginate to apex, widest point with large spine, emargination with row of short spines. Meso- and metatibiae straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus (Fig. 108) markedly arcuate in lateral view; parameres originating distally on main piece; distal piece comparatively small and simplified.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	etymology	Etymology. Named in reference to the totally pubescent metaventrite.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B27FFD0FF79F717FEDCFC16.taxon	distribution	Distribution. Currently known from eastern Area 1, and the Herzog Mts. in Area 6; elevation range 1220 – 1700 m (Fig. 479).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	description	(Figs. 107, 109, 400, 485)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (ZSM). Paratypes: Same data as holotype (7 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	diagnosis	Differential Diagnosis. Among members of the Velvetina group, somewhat similar in habitus to H. adelbertensis (Figs. 107, 110); these two species are the only members of the Velvetina group that have metaventral plaques (they are tiny). Hydraena ibalimi differs from H. adelbertensis by the slightly larger size (ca. 1.60 vs. 1.52 mm), the decidedly less hairy dorsum, and the proportionally larger elytra that are wider posteriorly; males additionally differentiated by the differently shaped metatibiae. The aedeagi of the two species also indicate a relationship, while differing distinctively in details (Figs. 109, 112).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.60 / 0.66; head 0.27 / 0.37; pronotum 0.39 / 0.43, PA 0.38, PB 0.33; elytra 0.94 / 0.66. Dorsum piceous, except light brown to testaceous band across anterior 2 / 7 of pronotum; legs dark brown to reddish brown; maxillary palpi light brown, tip slightly darker. Frons very slightly concave near eyes, punctures ca. 1 xef; interstices shining, 0.5 – 4 xpd. Clypeus microreticulate laterally, sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum more densely punctate, interstices shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin straight or very slightly arcuate; punctures on disc ca. 1 – 2 xpd those of frons; interstices shining, 1 – 2 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 shallow, extending in midline to about midlenth of pronotum; PF 2 deep, large, oval, oblique, medially confluent, conjointly forming U-shaped impression; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity slightly anterior to midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming very shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 2 / 9. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 5 / 3, sides slightly converging toward blunt apex. Plaques extremely small, narrow lines, raised posteriorly in tiny point, located on sides of deep median depression, hydrofuge pubescence longest lateral to median depression. AIS width at slightly arcuate posterior margin ca. 2.5 x P 2. All legs long and slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to slightly past midlength, then emarginate to apex, widest point with a few large spines, emargination with row of very short spines. Mesotibia straight. Metatibia very narrow, very slightly arcuate in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 109). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 400).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	etymology	Etymology. Named in honor of Papuan biologist Sentiko Ibalim, the collector of this and other new species of PNG Hydraena.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B26FFD7FF79F1F9FD0CFE62.taxon	distribution	Distribution. Currently known only from the type locality, Mianmin, in the far western part of Area 1, near the border with Area 2; elevation 1080 m (Fig. 485).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	description	(Figs. 110, 112, 486)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Adelbert Mts., below Keki, 790 m, 4 ° 42.3 ' S, 145 ° 25.089 ' E, 5 v 2006, Balke & Manaono (PNG 53) (ZSM). Paratypes (3): Madang Province: Same data as holotype (1 ZSM); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	diagnosis	Differential Diagnosis. Among members of the Velvetina group, somewhat similar in habitus to H. ibalimi, H. incista and H. copulata (Figs. 107, 110, 114); in addition to habitus similarities, all four species have the frons slightly concave. Hydraena adelbertensis differs from the compared species by the smaller size (ca. 1.52 vs. 1.60 – 1.78 mm); in addition, it differs from H. incista by the more transverse pronotum, and from H. copulata by the proportionally shorter elytra. Hydraena adelbertensis and H. ibalimi are the only species of the Velvetina group with metaventral plaques (they are tiny). Hydraena adelbertensis is differentiated from H. ibalimi by the hairy dorsum, the proportionally smaller elytra, and the differently shaped male metatibiae. The aedeagi of the two species also indicate a relationship, while differing distinctively in detailed structure (Figs. 109, 112).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.52 / 0.62; head 0.25 / 0.35; pronotum 0.39 / 0.44, PA 0.37, PB 0.32; elytra 0.87 / 0.62. Dorsum piceous, except light brown to testaceous band across anterior 1 / 4 of pronotum; legs brown to reddish brown; maxillary palpi light brown to testaceous, tip slightly darker. Frons slightly concave near eyes, punctures ca. 1 xef; interstices shining, 1 – 2 xpd. Clypeus microreticulate laterally, sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, anterior margin straight or very slightly arcuate; punctures on disc ca. 1 – 2 xpd those of frons, each puncture with short but distinctive seta; interstices shining, 1 – 3 xpd, punctures slightly larger and much denser at anterior and posterior; PF 1 very shallow; PF 2 deep, large, oval, oblique, very shallowly confluent; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior, some punctures subserial near base; each puncture with distinctive, short seta. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques extremely small, carinate, located on sides of deep median depression, hydrofuge pubescence longest lateral to median depression. AIS width at straight posterior margin ca. 2 x P 2. All legs long and slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to slightly past midlength, then emarginate to apex, widest point with a few large spines, emargination with row of very short spines. Mesotibia straight. Metatibia straight, medial margin slightly emarginate. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 112).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	etymology	Etymology. Named in reference to the geographical distribution, the Adelbert Mountains.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B21FFD7FF79F06AFDE7F821.taxon	distribution	Distribution. Currently known from two very narrowly separated localities in the Adelbert Mts., in Area 5; elevations 400 m and 790 m (Fig. 486).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	description	(Figs. 111, 113, 482)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Akameku – Brahmin, Bismarck Range, 750 m, 5 ° 49.307 ' S, 145 ° 24.389 ' E, 25 xi 2006, Balke & Kinibel (PNG 114) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	diagnosis	Differential Diagnosis. Immediately differentiated from other members of the Velvetina group by the densely micropunctulate dorsal surface of the head and pronotum (Fig. 111). The metaventral tumid areas, on each side of the median depression, are another distinctive character of the species. The aedeagus cannot be confused with those of the other members of the group (Fig. 113).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.72 / 0.68; head 0.25 / 0.39; pronotum 0.43 / 0.48, PA 0.41, PB 0.34; elytra 1.04 / 0.68. Dorsum piceous, except light brown band across anterior 1 / 6 of pronotum, legs brown to reddish brown, maxillary palpi testaceous to brown, distal 1 / 3 of last palpomere darker. Frons and clypeus densely strongly micropunctulate, dull, punctures obscured, ca. 1 xef. Mentum slightly concave, very sparsely very finely punctulate, shining; postmentum effacedly micropunctulate. Genae raised, shining, with tiny median impression, without posterior ridge. Pronotum cordiform, anterior margin straight or slightly arcuate; entirely densely micropunctulate, dull, punctures on disc obscured, ca. 1 xpd those of frons, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 extending posteriorly in midlongitudinal impression between PF 2; PF 2 deep, large, oval, oblique, very shallowly confluent; PF 3 deep; PF 4 moderately deep. Elytra convex, effacedly microreticulate, dull, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior, some punctures random near base. Intervals not raised, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques absent, hydrofuge pubescence longest on markedly tumid area on each side of deep median depression. AIS width at straight posterior margin slightly greater than 2 x P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to slightly past midlength, then emarginate to apex, widest point with several large spines, emargination with row of short spines, anterior margin slightly arcuate, widest at distal 2 / 3. Mesotibia straight. Metatibia straight. Abdominal apex symmetrical; last tergite (male) shallowly notched. Aedeagus (Fig. 113) in ventral aspect with main piece comparatively narrow and left paramere not visible; in left lateral view large process of distal piece in front of left paramere. Female not yet known.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	etymology	Etymology. " Big bubble "; named in reference to the large and strongly hydrofuge pubescent tumidities of the metaventrite, and the large bubble that would result from this morphology.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD6FF79F2BAFE50FA29.taxon	distribution	Distribution. Currently known only from the type locality in the Bismarck Range, in the eastern part of Area 2; elevation 750 m (Fig. 482).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	description	(Figs. 114, 116, 481)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	materials_examined	Type Material. Holotype (male): Western Highlands Province: Simbai, Kairong River, 1850 m, 5 ° 14.84 ' S, 144 ° 28.457 ' E, 2 iii 2007, Kinibel (PNG 139) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	diagnosis	Differential Diagnosis. Among members of the Velvetina group, somewhat similar in habitus to H. adelbertensis and H. copulata (Figs. 110, 114, 115); all three species have the frons slightly concave. Distinguished from both species by the pronotal shape (PL = PW vs. PL <PW), and the depressed mesoventral intercoxal process. The aedeagi of the three species distinctively differ (Figs. 112, 116, 117).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.71 / 0.68; head 0.27 / 0.37; pronotum 0.43 / 0.43, PA 0.37, PB 0.34; elytra 1.00 / 0.68. Dorsum piceous, except light brown to testaceous band across anterior 1 / 6 of pronotum, legs and maxillary palpi brown to reddish brown. Frons with depressed area next to each eye, punctures less than 1 xef; interstices 2 – 4 xpd; depressed areas microreticulate, very weakly shining, disc more strongly shining,. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum slightly concave, very sparsely very finely punctulate, shining; postmentum rather coarsely punctate and effacedly micropunctulate, weakly shining. Genae raised, except medially impressed, shining, without posterior ridge. Pronotum cordiform, anterior margin slightly arcuate; punctures on disc ca. 1 xef, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 shallow; PF 2 deep, large, oval, oblique, confluent, together forming U-shaped impression; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior, some punctures random near base. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. P 1 laminate; median carina very low, not sinuate in profile. P 2 not raised, very short, much shorter than and confluent with metaventral intercoxal process. Plaques absent, hydrofuge pubescence longest at sides of deep median depression. AIS width at straight posterior margin ca. 3 x P 2. All legs long and slender, except profemur more robust. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to ca. distal 1 / 4, then emarginate and with flat surface to apex, widest point with large spine, emargination with row of short spines. Mesotibia straight. Metatibia straight, with few setae on medial margin subapically; metatarsi with long setae on basal tarsomeres. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus (Fig. 116) distal piece with several smaller processes and one large, blunt process. Female not yet known.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	etymology	Etymology. " Out of the chest box "; named in reference to the very unusual, reduced condition of the mesoventral intercoxal process.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B20FFD5FF79F420FE2AFC5E.taxon	distribution	Distribution. Currently known only from the type locality, the Kairong River, in north-central Area 1; elevation 1850 m (Fig. 481).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	description	(Figs. 115, 117, 484)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	materials_examined	Type Material. Holotype (male): Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (ZSM). Paratype: Same data as holotype (1 female ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	diagnosis	Differential Diagnosis. Among members of the Velvetina group, somewhat similar in habitus to H. incista (Figs. 114, 115); distinguished therefrom by the wider pronotal shape (PL <PW vs. PL = PW), the non-depressed mesoventral intercoxal process, and the midlongitudinal extension of pronotal fovea PF 1. The aedeagi of the two species distinctively differ (Figs. 116, 117).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.78 / 0.72; head 0.26 / 0.37; pronotum 0.43 / 0.45, PA 0.37, PB 0.36; elytra 1.08 / 0.72. Dorsum piceous, except light brown to testaceous band across anterior 1 / 6 of pronotum, legs and maxillary palpi brown to reddish brown, distal 1 / 3 of last palpomere darker. Frons with depressed area next to each eye, punctures less than 1 xef; interstices 2 – 4 xpd; depressed areas microreticulate, dull or very weakly shining, disc more strongly shining,. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum concave, very sparsely very finely punctulate, shining. Genae raised, shining, with tiny median impression, without posterior ridge. Pronotum cordiform, anterior margin slightly arcuate; punctures on disc ca. 1 xef, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 with shallow midlongitudinal extension to ca. middle of disc; PF 2 deep, large, oval, oblique, confluent, together forming U-shaped impression; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity slightly before midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another. P 1 laminate; median carina very low, not sinuate in profile. P 2 not raised, very short, much shorter than and confluent with metaventral intercoxal process. Plaques absent, hydrofuge pubescence longest at sides of deep median depression. AIS width at straight posterior margin ca. 3 x P 2. All legs long and slender, except profemur more robust. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to ca. distal 1 / 4, then emarginate and with flat surface to apex, widest point with large spine, emargination with row of short spines. Mesotibia straight. Metatibia straight, with few setae on medial margin subapically; metatarsi with long setae on basal tarsomeres. Abdominal apex symmetrical; last tergite (male) notched. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques absent, hydrofuge pubescence longest at sides of deep median depression. AIS width at straight posterior margin ca. 2 x P 2. All legs long and very slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to slightly past midlength, then decreasing in width to slightly hooked apex, widest point with several large spines, between these spines and apex with row of short spines, anterior face of protibia flat. Meso- and metatibiae straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus (Fig. 117) distal piece with several smaller processes and one large, strong, hook-shaped process. Female with depressions on frons like those of male.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	etymology	Etymology. " Joined "; named in reference to the fact that the holotype and only known female were collected in copulo (Fig. 8), and also named in reference to the very strong and large hook-shaped process of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B23FFD4FF79F631FD87FD66.taxon	distribution	Distribution. Currently known only from the type locality near Marawaka, in the southeastern extreme of Area 1; elevation 1400 m (Fig. 484).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B22FFDBFF79F169FBBCFF61.taxon	description	(Figs. 118, 120, 480)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B22FFDBFF79F169FBBCFF61.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Umg. [= environs of] Onerunka, Ramu River, [GE est.] 1500 – 1700 m, 6 ° 20 ' S, 145 ° 47 ' E, 9 xii 1979, W. G. Ullrich (MHNG). Paratypes (2): Eastern Highlands Province: Umg. [= environs of] Igipinti, Korindaiop River, [GE est.] 600 – 1700 m, 6 ° 25 ' S, 145 ° 42 ' E, 18 vi 1979, W. G. Ullrich (1 MHNG); Wanitabi Valley, nr. Okapa, on partly rotted floating logs, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 176 a) (1 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B22FFDBFF79F169FBBCFF61.taxon	diagnosis	Differential Diagnosis. Among members of the Velvetina group, somewhat similar in habitus to H. incista (Figs. 114, 118), including having the pronotum length and width equal; differing therefrom by the larger size (ca. 1.89 vs. 1.71 mm), the lack of depressed areas on the frons, and the non-depressed mesoventral intercoxal process. The aedeagi of the two species distinctively differ (Figs. 116, 120).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B22FFDBFF79F169FBBCFF61.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.89 / 0.72; head 0.30 / 0.39; pronotum 0.47 / 0.47, PA 0.40, PB 0.37; elytra 1.11 / 0.72. Dorsum piceous, except light brown to testaceous band across anterior 1 / 5 of pronotum, legs and maxillary palpi brown to reddish brown. Frons punctures ca. 1 xef; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, with tiny median impression, without posterior ridge. Pronotum cordiform, anterior margin straight or slightly arcuate; punctures on disc ca. 1 xpd those of frons, interstices shining, 2 – 4 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 absent; PF 2 deep, large, oval, oblique, very shallowly confluent; PF 3 deep; PF 4 moderately deep. Elytra convex, summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior, some punctures random near base. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques absent, hydrofuge pubescence longest at sides of deep median depression. AIS width at straight posterior margin slightly greater than 2 x P 2. All legs long and very slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to slightly past midlength, then emarginate to apex, widest point with large spine, emargination with row of short spines. Mesotibia straight. Metatibia straight, medial margin very slightly emarginate. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus (Fig. 120) markedly arcuate in lateral view; distal piece with several processes. Females not yet known.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B22FFDBFF79F169FBBCFF61.taxon	etymology	Etymology. Named in reference to the shape of the pronotum, which has the length and width equal. Distribution. Currently known from a cluster of localities in eastern Area 1; elevation 1500 – 1700 m, but with one locality estimated (using Google Earth) broadly at 600 – 1700 m (Fig. 480).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	description	(Figs. 119, 121, 324 – 327, 401, 483)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (NHM). Paratypes (96): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (11 NHM); Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (71 NHM); Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (14 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	diagnosis	Differential Diagnosis. A moderately sized, darkly colored species with sexually dimorphic legs (SEM Figs. 325 – 327). Bearing some superficial similarity in habitus to H. fascinata (Figs. 119, 122); differentiated therefrom by the very different leg structure and very different aedeagi (Figs. 121, 124). The female tergite X, gonocoxite and spermatheca are very different in the two species (Figs. 401, 402). The plaques are unusual in that the medial margins are closer to one another in the middle than at either end. The aedeagus (Fig. 121) has unusual parameres. The metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 324 – 327).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.75 / 0.72; head 0.25 / 0.40; pronotum 0.42 / 0.50, PA 0.43, PB 0.42; elytra 1.08 / 0.72. Dorsum piceous; legs and maxillary palpi dark brown. Frons moderately fine, moderately densely punctate, punctures ca. 1 xef; interstices weakly shining, effacedly microreticulate, 1 – 4 xpd, punctures sparser on disc. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining, each puncture with moderately long recumbent seta; postmentum medially effacedly micropunctulate, otherwise finely sparsely punctate, shining. Genae raised, shining, without posterior ridge. Pronotum weakly cordiform, median 2 / 3 of anterior margin straight or very weakly emarginate; punctures on disc ca. 1 xpd largest punctures of frons, interstices effacedly microreticulate, dull, 1 – 2 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow; PF 2 moderately shallow, very shallowly confluent; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity slightly past midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, effacedly microreticulate, dull or very weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 4 / 11 / 3. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 8 / 3, sides slightly converging toward apex. Plaques wide, flat, closely spaced, medial margins converging slightly toward one another at midlength, located at sides of median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 x P 2. Middle and hind legs long and slender, front legs more robust. Profemur (male) with tubercle near trochanter; protibia very slightly arcuate, distal 1 / 3 widened on medial margin and bearing row of very short spines. Mesotibia very slightly arcuate, medial surface subapically notched. Metatibia straight, medial margin very slightly widened at ca. distal 1 / 3. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 119). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 401).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	etymology	Etymology. Named in reference to the geographical locality.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2DFFDAFF79F09FFEF2FE62.taxon	distribution	Distribution. Currently known only from the type locality near Okapa, in eastern Area 1; elevation 1372 m (Fig. 483). Note. In some specimens the medial margins of the plaques are more nearly parallel than they are in the holotype (Fig. 119).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	description	(Figs. 122, 124, 402, 487)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (NHM). Paratypes (143): Eastern Highlands Province: Marawaka, Ande, 1700 – 1800 m, 7 ° 1.697 ' S, 145 ° 49.807 ' E, 9 xi 2006, Balke & Kinibel (PNG 87) (35 MCZ, NHM, NMW, PNG, ZSM); Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex sand and gravel banks of small stream, but only in the 20 yards that it is permanent, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 19 x 1964, M. E. Bacchus (MEB 62) (13 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel bank of small river in places where rotten leaves had accumulated, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 73) (6 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel banks of small stream, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 74) (9 NHM); Finisterre Mts., Naho River Valley, Moro, 1691 m, 5 ° 50 ' S, 146 ° 7 ' E, 30 x – 23 xi 1964, M. E. Bacchus (MEB 78) (49 NHM); Finisterre Mts., Naho River Valley, Moro, ex muddy gravel banks of small stream, 1691 m, 5 ° 50 ' S, 146 ° 7 ' E, 3 xi 1964, M. E. Bacchus (MEB 83) (7 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (7 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex gravel banks of small fast stream, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 91) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. aquila; differentiated therefrom by the larger size (ca. 1.76 vs. 1.56 mm), the more elongate elytra, the less coarsely punctate dorsum, and the more narrowly spaced plaques (Figs. 122, 123). The male genitalia of the two species distinctively differ (Figs. 124, 125).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.76 / 0.73; head 0.28 / 0.39; pronotum 0.39 / 0.51, PA 0.42, PB 0.43; elytra 1.09 / 0.73. Dorsum piceous except narrow light brown to brown band along anterior margin of pronotum, occupying ca. 1 / 5 of pronotum as measured in midline; legs brown to dark brown; maxillary palpi brown, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 xef, interstices laterally microreticulate, dull, medially shining, ca. 2 – 5 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum microreticulate. Genae very slightly raised, shining, with very small, shallow, posteromedian impression, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; sides weakly emarginate between anterior angle and widest part; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly ca. 2 – 3 xpd those on disc; PF 1, PF 2 and PF 4 very shallow; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 9 / 2. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 2 / 1, transversely convex, sides parallel, apex blunt. Plaques large, slightly raised, at sloping sides of median depression, anteriorly very slightly tapering. Metaventrite between mesocoxae weakly raised in midline. AIS width at straight posterior margin slightly greater than P 2. All legs rather long and slender. Profemur (male) without tubercle on ventral margin; protibia straight, medial margin subapically emarginate, appearing weakly hooked, and with few short spines in emargination. Mesotibia straight, slender. Metatibia straight, slender, medial margin extremely slightly emarginate. Abdominal apex very slightly asymmetrical; last tergite (male) with apicomedian notch and fringe of setae. Aedeagus as illustrated (Fig. 124). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 402).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	etymology	Etymology. " Charm, enchant "; named in reference to the intricacy but yet clarity of the aedeagus, and to the simple but yet bold pattern of the male protibial setae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2CFFD9FF79F637FEE4FC7A.taxon	distribution	Distribution. Currently known from far eastern Area 1 (1700 – 1800 m) and localities in the Finisterre Mts., Area 5 (1220 – 1691 m) (Fig. 487). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	description	(Figs. 123, 125, 488)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Simbai area, 1200 m, 5 ° 13.389 ' S, 144 ° 37.285 ' E, 10 iii 2007, Kinibel (PNG 152) (ZSM). Paratypes: Same data as holotype (9 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. fascinata; differentiated therefrom by the smaller size (ca. 1.56 vs. 1.76 mm), the less elongate elytra, the more coarsely punctate dorsum, and the more widely spaced plaques (Figs. 122, 123. The male genitalia of the two species distinctively differ (Figs. 124, 125).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.56 / 0.65; head 0.26 / 0.37; pronotum 0.36 / 0.46, PA 0.39, PB 0.37; elytra 0.95 / 0.65. Dorsum piceous, except anterior angles of pronotum dark brown; legs dark brown; maxillary palpi light brown, tip of palpus slightly darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 5 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc slightly smaller than those of frons, interstices shining, 2 – 6 xpd, punctures much larger and denser at anterior and posterior; PF 1 shallow; PF 2 shallow; PF 3 deep; PF 4 shallow. Elytra transversely convex, summit of posterior declivity slightly before midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, some punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 3 / 9 / 3. P 1 laminate; median carina sinuate in profile. P 2 transversely roundly raised, l / w ca. 2 / 1, sides parallel for most of length. Plaques moderately wide posteriorly, weakly raised, medial margins parallel, located at sides of deep, median depression, each plaque tapering markedly from posterior to anterior. Metaventrite with very low, indistinct midlongitudinal ridge. AIS width at straight posterior margin slightly greater than P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia straight, lateral margin weakly arcuate, medial margin straight except indented subapically where located ca. two short spines. Mesotibia straight or extremely weakly arcuate. Metatibia arcuate, distal 1 / 2 of medial margin with sparse, long, hair-like setae. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 125).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	etymology	Etymology. The aedeagus recalls a screaming eagle.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2FFFD8FF79F612FD0CFE11.taxon	distribution	Distribution. Currently known only from the type locality, the Simbai area, in north central Area 1 near the border with Area 2; elevation 1200 m (Fig. 488).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	description	(Figs. 126, 128, 403, 489)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Akameku – Brahmin, Bismarck Range, 750 m, 5 ° 49.307 ' S, 145 ° 24.389 ' E, 25 xi 2006, Balke & Kinibel (PNG 114) (ZSM). Paratypes: Same data as holotype (17 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	diagnosis	Differential Diagnosis. Recognized by the narrow body form, the coarsely densely punctate dorsum, and the very narrow mesoventral intercoxal process (P 2). Neither the dorsal habitus nor the male genitalia show a close affinity with other species groups (Figs. 126, 128).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.39 / 0.56; head 0.23 / 0.33; pronotum 0.34 / 0.44, PA 0.36, PB 0.34; elytra 0.83 / 0.56. Dorsum of head dark brown to piceous; pronotum light brown to testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 13 / 4; elytra dark brown; legs light brown; maxillary palpi testaceous, tip very slightly darker. Dorsum weakly shining. Frons punctures ca. 2 xef near eyes, smaller and sparser medially; interstices shining, 1 – 3 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum effacedly microreticulate in posterior 1 / 2, otherwise finely sparsely punctulate. Genae very slightly raised, weakly shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; sides straight or very slightly emarginate between anterior angle and widest part, sinuate between widest part and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 1 – 2 xpd, punctures anteriorly and posteriorly denser than those on disc; PF 1 and PF 4 very shallow; PF 2 moderately deep, medially conjointly shallowly confluent; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, very weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 2.5 / 5 / 2. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 very narrow, length / width ca. 6 / 1, sides very slightly converging toward blunt apex. Plaques large, slightly raised, at sides of narrow median depression, anteriorly slightly tapering and slightly convergent. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. 4 x P 2. All legs of moderate length. Profemur (male) with minute tubercle on ventral margin near trochanter; protibia very slightly arcuate, increasing in width from base to apex. Mesotibia straight. Metatibia straight, very slightly increasing in width in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) with large, deep apicomedian notch.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	etymology	Etymology. Named in reference to the type locality.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2EFFDFFF79F14BFE50FEA9.taxon	distribution	Distribution. Currently known only from the type locality in the Bismarck Range, in the eastern part of Area 2; elevation 750 m (Fig. 489).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	description	(Figs. 127, 129, 490)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Aiome area, 130 m, 5 ° 10.593 ' S, 144 ° 42.8 ' E, 11 iii 2007, Kinibel (PNG 156) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	diagnosis	Differential Diagnosis. Somewhat similar in dorsal habitus and color to H. marawaka (Otiarca group) and H. foliobba (Foliobba group) (Figs. 50, 62, 127); differing from members of both groups by the modifications of the male legs and the form of the aedeagus. The setal brushes on the male meso- and metatibiae, and the markedly arcuate mesotibiae suggest relationship to H. mercuriala (Mercuriala group), and the aedeagus of H. quadriplumipes could represent a less derived condition for that group (Figs. 129, 132). Dorsally, H. quadriplumipes is immediately differentiated from H. mercuriala and H. ollopa (Figs. 127, 130, 131) by the distinctive pronotal fascia.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.73 / 0.68; head 0.29 / 0.41; pronotum 0.42 / 0.52, PA 0.45, PB 0.42; elytra 1.05 / 0.68. Dorsum of head piceous; pronotum testaceous in front of and behind dark brown to piceous fascia, ratios of color bands, as measured in midline, ca. 8 / 11 / 3; elytra dark brown; legs light brown; maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 xef; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum effacedly micropunctulate. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc slightly larger and deeper than those of frons, interstices shining, 1 – 2 xpd, punctures larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 deep; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3.5 / 1 / 7 / 4. P 1 laminate; median carina sinuate in profile. P 2 weakly raised, l / w as ca. 5 / 3.5, sides slightly converging toward blunt apex. Plaques carinate lines, height gradually increasing from anterior to posterior, parallel, located at sides of deep, median depression. Metaventrite without midlongitudinal ridge. AIS width at arcuate posterior margin ca. 1.7 x P 2. All legs moderately long and slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia very slightly arcuate, gradually increasing in width from base to apex, distal 1 / 5 of medial margin with row of closely spaced, very short spines. Mesotibia markedly arcuate, distal 1 / 3 markedly widened; mesotarsus with brush of setae on basal tarsomeres. Metatibia very weakly arcuate, distal 1 / 2 of medial margin with hair-like setae that lie flat on cuticle in dry specimens; metatarsus with small brush of setae on basal tarsomeres. Abdominal apex symmetrical; last tergite (male) notched.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	etymology	Etymology. Named in reference to the meso- and metatarsal setal brushes.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B29FFDEFF79F14BFC7FFEF2.taxon	distribution	Distribution. Currently known only from the type locality, the Aiome area, in central Area 2; elevation 130 m (Fig. 490). Perhaps to be expected also in Area 3, based on the elevation.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	description	(Figs. 130, 132, 404, 491)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	materials_examined	Type Material. Holotype (male): Sandaun Province: May River, ex river side pool, 970 m, 4 ° 49.779 ' S, 141 ° 38.174 ' E, 19 x 2003, K. Sagata (WB 41) (ZSM). Paratypes (62): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (2 ZSM); Madang Province: Simbai area, 1200 m, 5 ° 13.389 ' S, 144 ° 37.285 ' E, 10 iii 2007, Kinibel (PNG 152) (16 MCZ, NHM, NMW, PNG, ZSM); Sandaun Province: Same data as holotype (2 ZSM); Mianmin, 670 m, 4 ° 53.292 ' S, 141 ° 34.118 ' E, 20 x 2008, S. Ibalim (PNG 191) (2 ZSM); same locality, 22 x 2008, S. Ibalim (PNG 189) (1 ZSM); Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (4 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (8 MCZ, NHM, NMW, PNG, ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (15 MCZ, NHM, NMW, PNG, ZSM); Ofektamin, 820 m, 5 ° 4.113 ' S, 141 ° 35.841 ' E, 17 x 2008, S. Ibalim (PNG 190) (12 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	diagnosis	Differential Diagnosis. Very similar in external characters to H. ollopa (Figs. 130, 131). Reliable determinations will require examination of the distinctively different male genitalia (Figs. 132, 133).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.92 / 0.80; head 0.29 / 0.43; pronotum 0.44 / 0.52, PA 0.44, PB 0.43; elytra 1.14 / 0.80. Dorsum piceous; legs brown; maxillary palpi brown except distal 1 / 2 of last palpomere darker. Frons moderately coarsely, moderately densely punctate, punctures ca. 1 – 2 xef; interstices shining, 0.5 – 5 xpd, punctures smallest and sparser on disc. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining, each puncture with moderately long recumbent seta; postmentum medially micropunctulate in small subtriangular area, otherwise finely sparsely punctate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd largest punctures of frons, interstices shining, 1 – 2 xpd, punctures slightly larger and denser at posterior; PF 1 very shallow; PF 2 moderately deep, very shallowly confluent; PF 3 deep; PF 4 moderately deep. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 10 / 7. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 2, sides slightly converging toward apex. Plaques moderately wide, flat, converging slightly from posterior to anterior, located at sides of deep median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.5 x P 2. All legs long and slender. Profemur (male) without tubercle near trochanter; protibia straight. Mesotibia slightly arcuate, medial surface widened and with small tubercle subapically. Metatibia moderately arcuate in distal 1 / 2; metatarsus with large brush of setae on ventral surface of basal tarsomeres. Abdominal apex slightly asymmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 132) with large lobe on ventral face of main piece; distal piece very complicated, with cluster of large, strongly sclerotized spines on left side. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 404).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	etymology	Etymology. Named in reference to the mythological Mercury, who had wings on his heels; males have a large setal brush on the hind tarsi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B28FFDDFF79F1C3FCC8FD3E.taxon	distribution	Distribution. Appears to track Area 2 rather well; found at several localities in the Mianmin area (670 – 1080 m) and two sites in eastern Area 2 (1200 m and 700 m) (Fig. 491).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	description	(Figs. 131, 133, 492)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	materials_examined	Type Material. Holotype (male): Western Highlands Province: Kundum, 1400 m, 5 ° 16.096 ' S, 144 ° 27.869 ' E, 3 iii 2007, Kinibel (PNG 142) (ZSM). Paratypes (64): Western Highlands Province: Same data as holotype (21 MCZ, NHM, NMW, PNG, ZSM); Lugup River, 1700 m, 5 ° 17.237 ' S, 144 ° 28.214 ' E, 4 iii 2007, Kinibel (PNG 143) (43 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	diagnosis	Differential Diagnosis. Very similar in external characters to H. mercuriala (Figs. 130, 131). Reliable determinations will require examination of the distinctively different male genitalia (Figs. 132, 133).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.95 / 0.82; head 0.32 / 0.44; pronotum 0.45 / 0.53, PA 0.47, PB 0.46; elytra 1.19 / 0.82. Dorsum piceous; legs brown; maxillary palpi brown except distal 1 / 2 of last palpomere darker. Frons moderately coarsely, moderately densely punctate, punctures ca. 1 – 2 xef; interstices shining, 0.5 – 5 xpd, punctures sparser on disc. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining, each puncture with moderately long recumbent seta; postmentum medially micropunctulate, otherwise finely sparsely punctate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; punctures on disc ca. 1 xpd largest punctures of frons, interstices shining, 1 – 2 xpd, punctures slightly larger and denser at posterior; PF 1 very shallow; PF 2 moderately deep, very shallowly confluent; PF 3 deep; PF 4 moderately deep. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 10 / 6. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 2, sides slightly converging toward apex. Plaques moderately wide, flat, converging slightly from posterior to anterior, located at sides of deep median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.6 x P 2. All legs long and slender. Profemur (male) with tubercle near trochanter; protibia straight, except subapically bent, forming process on medial surface that, when leg flexed, opposes tubercle of femur. Mesotibia slightly arcuate, medial surface subapically widened and with small tubercle. Metatibia moderately arcuate in distal 1 / 2; metatarsus with large brush of setae on ventral surface of basal tarsomeres. Abdominal apex slightly asymmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 133) with large, very complicated distal piece, best viewed in dorsal aspect; left paramere very large, sinuate.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	etymology	Etymology. The specific epithet is an anagram of Apollo; the mythological Apollo was the brother of Mercury. The name is to be treated as a noun.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2BFFDDFF79F0DCFE43F862.taxon	distribution	Distribution. Currently known from two very narrowly separated localities in north central Area 1; elevations 1400 m and 1700 m (Fig. 492).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	description	(Figs. 134, 136, 328 – 333, 405, 493)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (NHM). Paratypes (336): Eastern Highlands Province: Same data as holotype (4 NHM); Okapa, on wet rocks above waterline, fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183 a) (2 NHM); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (3 NHM); Wanitabi Valley, nr. Okapa, gravel banks of small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 a) (7 NHM); Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (2 NHM); Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex gravel banks of large river, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 18 x 1964, M. E. Bacchus (MEB 61) (23 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel banks of small stream, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 74) (1 NHM); Finisterre Mts., Naho River Valley, Budemu – Kikipei track, ex gravel bank of small river in places where rotten leaves had accumulated, 1220 m, 5 ° 56 ' S, 146 ° 40 ' E, 24 x 1964, M. E. Bacchus (MEB 73) (3 NHM); Finisterre Mts., Naho River Valley, Moro, 1691 m, 5 ° 50 ' S, 146 ° 7 ' E, 30 x – 23 xi 1964, M. E. Bacchus (MEB 78) (68 NHM); Finisterre Mts., Naho River Valley, Moro, nr. Sewe, gravel bank of small stream running into River Naho, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 2 xi 1964, M. E. Bacchus (MEB 81) (70 NHM); Finisterre Mts., Naho River Valley, Moro, small stream running into River Naho, ex crevices in vertical rock, heavy water flow, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 2 xi 1964, M. E. Bacchus (MEB 80) (97 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (25 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex gravel banks of small fast stream, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 91) (16 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex tiny puddles left in clay bottom of partly ephemeral pool, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 92) (5 NHM); Finisterre Mts., Naho River Valley, nr. Sewe, large flat area of wet gravel with small rivulets running through it, 1615 m, 5 ° 51 ' S, 146 ° 8 ' E, 15 xi 1964, M. E. Bacchus (MEB 95) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	diagnosis	Differential Diagnosis. Males differentiated from other species, except the putative sister species H. sexsuprema, by the strongly arcuate meso- and metatibiae; females recognized by the concave frons (Figs. 134, 135). Males differentiated from those of H. sexsuprema by the slightly larger size (ca. 1.86 vs. 1.78 mm), the markedly widened tips of the mesotibiae, the lack of a brush of setae on the metatibiae, and the longer, more narrowly separated plaques (ratios ca. 4 / 1 / 8 / 6 vs. 4 / 1 / 6 / 8). The male genitalia of the two species share a basic plan, but differ distinctively in shapes of the parameres, among other features (Figs. 136, 137). The exocrine pore areas of the female head and pronotum, as well as the structure of the metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 328 – 333).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.86 / 0.80; head 0.31 / 0.44; pronotum 0.46 / 0.55, PA 0.47, PB 0.46; elytra 1.12 / 0.80. Dorsum dark brown to piceous; legs and maxillary palpi dark brown. Frons markedly microreticulate, except effacedly microreticulate. on middle of disc, punctures ca. 1 xef; interstices 1 – 5 xpd. Clypeus microreticulate laterally, finely, moderately sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining; postmentum medially micropunctulate, moderately dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; microreticulate, more strongly laterally and in PF 2 than on disc; punctures on disc ca. 1 – 2 xpd largest punctures of frons, interstices dull, 1 – 2 xpd, punctures slightly larger and denser at posterior; PF 1 absent or extremely shallow; PF 2 deep, very shallow confluent; PF 3 deep; PF 4 moderately deep. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, some punctures random, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 8 / 6. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 2, sides slightly converging toward apex. Plaques carinate, very narrow, located at sides of deep, wide median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.5 x P 2. All tibiae strongly arcuate, especially meso- and metatibiae. Profemur (male) with small, sharply pointed tubercle on medial surface short distance from trochanter. Mesotibia markedly widened in distal 1 / 4, widest and with small tubercle subapically. Metatibia without brush of setae. Abdominal apex slightly asymmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 136), in ventral view, with sharp ridge on proximal part of main piece; distal piece large and complex; left paramere in lateral aspect very wide, with setae along distal margin, ventral margin with tight cluster of long, wavy setae. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 405).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	etymology	Etymology. Named in reference to the markedly sexually dimorphic legs and head, and to the relationship to H. sexsuprema.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B2AFFC3FF79F134FF64FB52.taxon	distribution	Distribution. Currently known from eastern Area 1 and the Finisterre Mts. in Area 5; elevation range 1220 – 1691 m (Fig. 493). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	description	(Figs. 135, 137, 494)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (NHM). Paratypes (93): Madang Province: Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (73 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of small fast river, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 37) (10 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	diagnosis	Differential Diagnosis. Males differentiated from other species, except the putative sister species H. supersexa, by the strongly arcuate meso- and metatibiae; females recognized by the concave frons (Figs. 134, 135). Males differentiated from those of H. supersexa by the slightly smaller size (ca. 1.78 vs. 1.86 mm), the less markedly widened tips of the mesotibiae, the presence of a brush of setae on the metatibiae, and the shorter, more widely separated plaques (ratios ca. 4 / 1 / 6 / 8 vs. 4 / 1 / 8 / 6). The male genitalia of the two species share a basic plan, but differ distinctively in shapes of the parameres, among other features (Figs. 136, 137).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.78 / 0.72; head 0.28 / 0.41; pronotum 0.41 / 0.51, PA 0.43, PB 0.42; elytra 1.08 / 0.72. Dorsum dark brown to piceous; legs and maxillary palpi dark brown. Frons markedly microreticulate, except effacedly microreticulate. on middle of disc, punctures ca. 1 xef; interstices 1 – 5 xpd. Clypeus microreticulate laterally, finely, moderately sparsely punctate medially. Mentum very sparsely very finely punctulate, strongly shining; postmentum medially micropunctulate, moderately dull. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2 / 3 of anterior margin emarginate; microreticulate, more strongly laterally and in PF 2 than on disc; punctures on disc ca. 1 – 2 xpd largest punctures of frons, interstices dull, 1 – 2 xpd, punctures slightly larger and denser at posterior; PF 1 shallow; PF 2 deep, very shallow confluent; PF 3 deep; PF 4 moderately deep. Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, few punctures random near base, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 6 / 8. P 1 laminate; median carina sinuate in profile. P 2 raised, l / w ca. 3 / 2, sides slightly converging toward apex. Plaques carinate, very narrow, located at sides of deep, wide median depression. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 1.5 x P 2. All tibiae strongly arcuate, especially meso- and metatibiae. Profemur (male) with small, sharply pointed tubercle on medial surface short distance from trochanter. Metatibia with brush of setae subapically on medial surface. Abdominal apex slightly asymmetrical; last tergite (male) deeply notched. Aedeagus (Fig. 137), in ventral view, appearing markedly bent near midlength; left paramere in lateral aspect very wide, with setae along most of margin, ventral margin emarginate.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	etymology	Etymology. Named in reference to the markedly sexually dimorphic legs and head, and to the relationship to H. supersexa.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B35FFC2FF79F73FFC2AFC32.taxon	distribution	Distribution. Currently known from the Naho River Valley in the Finisterre Mts., elevation range 762 – 1082 m (Fig. 137). This is in Area 5, but at or very near the border of Area 3.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	description	(Figs. 138, 140, 562)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, 4.5 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (MCZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	diagnosis	Differential Diagnosis. A very small species (ca. 1.16 mm) with a rectangular pronotal macula (Fig. 138). This species may be confused with small members of the Manulea group, but distinctively differs therefrom in the form of the male genitalia. Hydraena brahman is a member of the Rudallensis group, which has eleven Australian species. Examination of the male genitalia will be necessary for reliable determinations (Fig. 140).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.16 / 0.47; head 0.20 / 0.30; pronotum 0.30 / 0.38, PA 0.32, PB 0.35; elytra 0.67 / 0.47. Dorsum of head with frons dark brown to piceous, clypeus and labrum brown; pronotum testaceous around brown, very diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 5 / 10 / 4; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices shining, medially 1 – 3 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctulate. Genae very slightly raised, shining, without posterior ridge. Pronotum transverse, median 1 / 2 of anterior margin emarginate; sides slightly arcuate between anterior angle and widest part, very weakly sinuate between widest part and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 1 – 3 xpd, punctures anteriorly and posteriorly slightly larger and denser than those on disc; PF 1 and PF 4 very shallow or absent; PF 2 shallow, obsolete; PF 3 shallow, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior; each puncture with distinct recumbent seta that attains next serial puncture. Intervals not raised, very weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect very slightly separately rounded, in posterior aspect margins forming moderate angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 5 / 4. P 1 laminate; median carina very slightly sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 2, sides very slightly converging toward blunt apex. Plaques carinate lines, at sides of deep median depression, anteriorly slightly convergent. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. 2 x P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia slightly arcuate, gradually increasing in width from base to apex. Mesotibia straight. Metatibia very slightly arcuate, slender. Abdominal apex very slightly asymmetrical; last tergite (male) with small apical notch, slightly offset to left side. Aedeagus as illustrated (Fig. 140).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	etymology	Etymology. Named in reference to the type locality.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B34FFC1FF79F45CFBFCFBEA.taxon	distribution	Distribution. Currently known only from the type locality near Brahman; this is in the eastern arm of Area 3, elevation 130 – 150 m (Fig. 562). Hydraena brahman is the putative sister species of the Australian species H. ambiosina, which has distribution records around the Gulf of Carpenteria (Fig. 561).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	description	(Figs. 139, 141, 470)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	materials_examined	Type Material. Holotype (male): Central Province: Port Moresby – Brown River road, ex small pool in dry gravelly stream bed, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 196) (NHM). Paratypes: Same data as holotype (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	diagnosis	Differential Diagnosis. Somewhat similar in dorsal habitus to H. spinobesa and H. reticulobesa (Figs. 139, 142, 143); differentiated from those members of the Spinobesa group by the non-microreticulate interstices of the head and pronotum, the generally more prominent setae of the dorsum, the presence of a pronotal macula, and the carinate metaventral plaques. The male genitalia of the three species are abundantly distinct (Figs. 141, 144, 145).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.20 / 0.49; head 0.19 / 0.28; pronotum 0.30 / 0.39, PA 0.31, PB 0.31; elytra 0.71 / 0.49. Dorsum of head dark brown; pronotum light brown around brown, very diffusely margined, faint rectangular macula, ratios of color bands, as measured in midline, ca. 5 / 10 / 5; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker. Dorsum very weakly shining. Frons punctures rather coarse, ca. 2 xef near eyes, smaller and slightly sparser medially; interstices shining, 1 – 2 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, strongly shining. Postmentum effacedly microreticulate in posterior 1 / 2, otherwise finely sparsely punctulate. Genae very slightly raised, shining, with very small, shallow, obsolete median impression, without posterior ridge. Pronotum weakly cordiform, median 1 / 2 of anterior margin emarginate; sides very slightly emarginate between anterior angle and widest part, sinuate between widest part and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 1 – 2 xpd, punctures posteriorly slightly larger and denser than those on disc; PF 1 and PF 4 very shallow or absent; PF 2 shallow, obsolete; PF 3 wide, shallow. Elytra transversely convex, widest at about midlength; summit of posterior declivity slightly anterior to midlength; lateral explanate margins moderately wide; punctures coarse, on basal 1 / 3 punctures ca. 2 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, very weakly shining, on disc ca. 0.5 – 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rather sharply rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 5 / 4. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 2, sides parallel, apex blunt. Plaques carinate lines, gradually increasing in height from anterior to posterior, at sides of median depression, anteriorly very slightly convergent. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. 1.5 x P 2; slightly narrower than separation of plaques. All legs of moderate length, femora rather stout. Profemur (male) without tubercle on ventral margin; protibia very slightly arcuate, rather stout, gradually increasing in width from base to subapically, then narrowed. Mesotibia straight. Metatibia very slightly, if at all, arcuate, slender. Abdominal apex symmetrical; last tergite (male) with very small apicomedian notch.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	etymology	Etymology. Dedicated to the famous physicist.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B37FFC0FF79F41BFE30FBCE.taxon	distribution	Distribution. Currently known only from the type locality near Port Moresby, Area 11; elevation estimated at 50 – 100 m (Fig. 470).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	description	(Figs. 142, 144, 334 – 336, 406, 496)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Budemu, ex sand and gravel banks of small stream, but only in the 20 yards that it is permanent, 1264 m, 5 ° 56 ' S, 146 ° 40 ' E, 19 x 1964, M. E. Bacchus (MEB 62) (NHM). Paratypes (47): Eastern Highlands Province: Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (10 NHM); Madang Province: Same data as holotype (4 NHM); Finisterre Mts., Naho River Valley, Moro, nr. Sewe, gravel bank of small stream running into River Naho, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 2 xi 1964, M. E. Bacchus (MEB 81) (2 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex dead leaves and muddy gravel by small stream, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 5 xi 1964, M. E. Bacchus (MEB 88) (10 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex gravel banks of small fast stream, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 91) (10 NHM); Finisterre Mts., Naho River Valley, nr. Moro, ex tiny puddles left in clay bottom of partly ephemeral pool, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 92) (11 NHM). The metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 334 – 336).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	diagnosis	Differential Diagnosis. Similar in body proportions and size (ca. 1.28 vs. 1.23 mm) to H. saluta (Figs. 142, 147); differentiated therefrom by the more densely punctate pronotum, the narrower P 2, and the narrower plaques (ratios ca. 1 / 1 / 4 / 4 vs. 2 / 1 / 3 / 1.5). The aedeagi of the two species distinctively differ (Figs. 144, 149). The metaventrite, abdominal apex, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 334 – 336).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.28 / 0.56; head 0.21 / 0.33; pronotum 0.29 / 0.44, PA 0.38, PB 0.38; elytra 0.78 / 0.56. Dorsum dark brown to piceous; legs light brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger and denser near eyes than medially; interstices effacedly microreticulate, dull or weakly shining, 1 – 3 xpd. Clypeus microreticulate laterally, finely, moderately densely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum transverse (PL / PW ca. 0.66), ca. median 3 / 5 of anterior margin very slightly arcuate to posterior; coarsely, densely punctate, punctures on disc ca. 3 xpd frons punctures, interstices on disc shining, 1 – 2 xpd, punctures slightly smaller and denser at anterior and posterior; sculpture laterally microreticulate and densely punctate, subrugulose; PF 1 absent or very shallow, obsolete; PF 2 shallow; PF 3 shallow; PF 4 absent. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 4 / 4. P 1 laminate; median carina sinuate in profile. P 2 very narrow, raised slightly at tip, l / w ca. 5 / 1, sides slightly converging toward apex. Plaques very narrow, weakly raised, converging slightly anteriorly, at sides of median depression that continues shallowly to tip of P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 3 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest slightly past midlength, medial margin very slightly emarginate, lateral margin arcuate and bearing short stout spines in widest part. Mesotibia straight, lateral margin slightly arcuate and bearing contiguous row of short stout spines. Metatibia very weakly, if at all, arcuate, gradually increasing in width from base to apex, medial margin with few moderately long setae in distal 1 / 3, lateral margin with some short spines in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 144). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 406).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	etymology	Etymology. Named in reference to the spinose tibiae and to the wide body.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B31FFC7FF79F2BAFDA2F8F9.taxon	distribution	Distribution. Currently known from Okapa, in the eastern part of Area 1 (1524 m), and localities in the Finisterre Mts. of Area 5 (1264 – 1432 m) (Fig. 496). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	description	(Figs. 143, 145, 499)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Moro, 1691 m, 5 ° 50 ' S, 146 ° 7 ' E, 30 x – 23 xi 1964, M. E. Bacchus (MEB 78) (NHM). Paratypes (11): Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (1 ZSM); Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (9 NMW); Western Highlands Province: Lugup River, 1700 m, 5 ° 17.237 ' S, 144 ° 28.214 ' E, 4 iii 2007, Kinibel (PNG 143) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	diagnosis	Differential Diagnosis. Similar in size (ca. 1.47 mm) and body proportions to H. owenobesa (Figs. 143, 146); differentiated therefrom by the entirely markedly microreticulate pronotum, the smaller metaventral plaques (ratios ca. 1 / 1 / 2 / 4 vs. 1 / 1 / 5 / 4), and the narrower and slightly longer P 2. The aedeagi of the two species have some general plan similarities, but distinctively differ in many details (Figs. 145, 148).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.47 / 0.66; head 0.22 / 0.37; pronotum 0.34 / 0.51, PA 0.40, PB 0.43; elytra 0.92 / 0.66. Dorsum dark brown to piceous; legs brown; maxillary palpi light brown, tip slightly darker. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices markedly microreticulate laterally, dull, effacedly microreticulate medially, very weakly shining, 1 – 4 xpd medially. Clypeus microreticulate laterally, finely, moderately densely punctate medially. Mentum and postmentum very sparsely finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum transverse (PL / PW ca. 0.67), ca. median 3 / 5 of anterior margin very slightly emarginate; markedly microreticulate, dull, punctures on disc ca. 1 – 2 xpd frons punctures, interstices on disc 1 – 3 xpd, punctures slightly denser at anterior and posterior; sculpture laterally markedly microreticulate, punctures obscured; PF 1 shallow; PF 2 deep, lateral margins roundly raised, shallowly confluent medially; PF 3 and PF 4 deep. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins narrow; on basal 1 / 3 punctures slightly larger than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 2 / 4. P 1 laminate; median carina sinuate in profile. P 2 very narrow, raised slightly at tip, l / w ca. 6 / 1, sides slightly converging toward apex. Plaques very small and indistinct ovals basally at sides of median depression that does not continue anteriorly to tip of P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 3 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest at distal 1 / 3, medial margin slightly emarginate at midlength, lateral margin arcuate, ventral margin bearing short stout spines in widest part. Mesotibia straight, lateral margin slightly arcuate, lateral and ventral margins each bearing row of short stout spines. Metatibia very weakly, if at all, arcuate, gradually increasing in width from base to apex, medial margin with few moderately long setae in distal 1 / 3, lateral margin with some short spines in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 145).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	etymology	Etymology. Named in reference to the markedly microreticulate dorsum, and broad body form.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC6FF79F2BAFD71F9D9.taxon	distribution	Distribution. Currently known from Areas 1, 5, and 7; elevation range 1000 – 1700 m, with one locality below and three localities at or above 1600 m (Fig. 499).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	description	(Figs. 146, 148, 407, 501)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (NMW). Paratypes: Same data as holotype (17 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	diagnosis	Differential Diagnosis. Similar in size (ca. 1.45 mm) and body proportions to H. reticulobesa (Figs. 143, 146); differentiated therefrom by the less markedly microreticulate pronotal disc, the shallower pronotal impressions, the larger metaventral plaques (ratios ca. 1 / 1 / 5 / 4 vs. 1 / 1 / 2 / 4), and the wider and slightly shorter P 2. The aedeagi of the two species have some general plan similarities, but distinctively differ in many details (Figs. 145, 148).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.45 / 0.61; head 0.23 / 0.34; pronotum 0.33 / 0.49, PA 0.39, PB 0.40; elytra 0.89 / 0.61. Dorsum dark brown to piceous; legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices microreticulate and dull laterally, effacedly microreticulate and weakly shining medially, 1 – 3 xpd. Clypeus microreticulate laterally, effacedly microreticulate medially, finely, sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum transverse (PL / PW ca. 0.67), ca. median 3 / 5 of anterior margin very slightly emarginate; moderately coarsely, densely punctate, punctures on disc ca. 2 xpd frons punctures, interstices on disc effacedly microreticulate, weakly shining, 1 – 2 xpd, interstices microreticulate and dull in impressions, punctures denser at anterior and posterior; PF 1 shallow, obsolete; PF 2 shallow; PF 3 moderately deep; PF 4 shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 5 / 4. P 1 laminate; median carina sinuate in profile. P 2 very narrow, raised slightly at tip, l / w ca. 6 / 1, sides slightly converging toward apex. Plaques very narrow, not raised, anteriorly tapering to point and converging slightly, at sides of median depression, depression does not continue to tip of P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 4 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest slightly past midlength, medial margin very slightly emarginate, lateral margin arcuate and bearing short stout spines in widest part. Mesotibia straight, lateral margin slightly arcuate, lateral and ventral margins each bearing row of short stout spines. Metatibia straight, medial margin in distal 2 / 3 weakly emarginate and with few moderately long setae, lateral margin with some short spines in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 148). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 407).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	etymology	Etymology. Named in reference to its geographic distribution in the Owen Stanley Range, and its placement in the Spinobesa group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B30FFC5FF79F48FFEB8FB7E.taxon	distribution	Distribution. Currently known only from the type locality near Garaina Saureri in Area 7; elevation 1600 m (Fig. 501).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	description	(Figs. 147, 149, 337 – 339, 495)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (NHM). Paratypes (18): Madang Province: Adelbert Mts., Sewan, 350 m, 4 ° 41.011 ' S, 145 ° 26.912 ' E, 3 v 2006, Balke & Manaono (PNG 50) (2 ZSM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (9 NHM); Keki – Sewan, Adelbert Mts., 300 m, 4 ° 40.558 ' S, 145 ° 27.187 ' E, 30 xi 2006, Binatang Boys (PNG 121) (3 ZSM); Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (1 NMW); Morobe Province: Kassam Pass, Yung Creek, [GE est.] 1300 – 1500 m, 6 ° 12 ' S, 146 ° 0 ' E, 14 vi 1979, W. G. Ullrich (1 MHNG); Western Highlands Province: Jimi Valley, Sendiap Station, 500 – 600 m, 5 ° 20.728 ' S, 144 ° 27.401 ' E, 5 iii 2007, Kinibel (PNG 146) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Spinobesa group by the very sparsely punctate pronotum that has moderately large impunctate areas anterior and lateral to each foveae PF 2, the comparatively large metaventral plaques, and the very small body size (ca. 1.23 mm) (Fig. 147). The aedeagus distinctively differs, most notably in the shapes of the parameres, from that of other members of the group (Fig. 149). The very complicated chaetotaxy of the protibia is illustrated with SEMs (Figs. 337 – 339).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.23 / 0.56; head 0.18 / 0.33; pronotum 0.29 / 0.44, PA 0.36, PB 0.37; elytra 0.79 / 0.56. Dorsum dark brown to piceous; legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger and denser near eyes than medially; interstices effacedly microreticulate, weakly shining, 1 – 3 xpd. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum transverse (PL / PW ca. 0.66), ca. median 3 / 5 of anterior margin very slightly arcuate to posterior; punctures on center of disc ca. 2 – 3 xpd frons punctures, interstices on disc shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; moderately large impunctate area anterior to and lateral to each PF 2; sculpture laterally densely punctate, subrugulose in PF 4; PF 1 very shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 3 / 1.5. P 1 laminate; median carina sinuate in profile. P 2 raised slightly at tip, l / w ca. 5 / 3, sides parallel, apex blunt. Plaques narrow, parallel, weakly raised except minutely carinate basally, at sides of median depression that continues shallowly to tip of P 2. AIS width at straight posterior margin almost 2 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, widest slightly past midlength, lateral margin arcuate and bearing short stout spines in widest part. Mesotibia straight, lateral margin slightly arcuate and bearing prominent, nearly contiguous row of short stout spines. Metatibia straight, gradually increasing in width from base to apex, medial margin with few moderately long setae in distal 1 / 3. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 149).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	etymology	Etymology. " Greet, salute "; named in reference to the prominent right paramere which extends beyond the aedeagal apex.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B33FFC4FF79F711FA8DFBEA.taxon	distribution	Distribution. Having a broad elevation range of 160 – 1500 m, but with only one locality above 914 m; currently known from Areas 1 – 3, and 5, basically in and on each side of the eastern part of Area 3 (Fig. 495).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	description	(Figs. 150, 152, 502)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	materials_examined	Type Material. Holotype (male): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, under wet moss on rocky seepage, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 201) (NHM). Paratypes: Same data as holotype (20 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	diagnosis	Differential Diagnosis. Similar to H. limbobesa in body proportions and the coarse and dense dorsal punctation (Figs. 150, 151); differing therefrom by the pronotal sides emarginate between the anterior angle and the widest part, the more evident microreticulation of the head and pronotum, and the slightly larger size (ca. 1.43 vs. 1.36 mm). The metaventral plaques are quite similar in the two species. The male genitalia of the two species differ distinctively; reliable determinations will require dissections (Figs. 152, 153).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.44 / 0.61; head 0.23 / 0.36; pronotum 0.36 / 0.48, PA 0.38, PB 0.43; elytra 0.86 / 0.61. Dorsum dark brown, head and pronotal disc piceous; legs brown; maxillary palpi light brown, tip not darker. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices microreticulate and dull laterally, effacedly microreticulate and very weakly shining medially, 1 – 2 xpd. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum dull, effacedly microreticulate and very sparsely very finely punctulate, postmentum microreticulate medially, finely punctate and shining anteriorly and laterally. Genae raised, shining, without posterior ridge. Pronotum moderately transverse (PL / PW ca. 0.75), ca. median 3 / 5 of anterior margin very slightly emarginate; sides slightly emarginate between anterior angle and widest part; coarsely, densely punctate, punctures on disc much deeper and ca. 3 – 4 xpd frons punctures, interstices on disc effacedly microreticulate, weakly shining, narrow walls to 1 xpd, interstices microreticulate and dull in impressions, punctures denser at anterior and posterior; PF 1 shallow, obsolete; PF 2 shallow; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 5 / 4. P 1 laminate; median carina sinuate in profile. P 2 narrow, raised slightly, l / w ca. 3 / 1, sides slightly diverging toward apex. Rim of mesocoxal cavity produced as very short carina on metaventrite. Plaques very narrow, weakly raised, converging slightly anteriorly, at sides of median depression that does not continue to P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest at about distal 1 / 3, medial margin very slightly emarginate, lateral margin weakly arcuate. Mesotibia straight, lateral margin slightly arcuate and bearing contiguous row of short stout spines. Metatibia straight, very slightly widened, widest at about distal 1 / 3. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 152).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	etymology	Etymology. Named in reference to its geographic distribution in the South Papuan Peninsula Foreland (Area 11), and its placement in the Spinobesa group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B32FFCBFF79F6E7FE25FC82.taxon	distribution	Distribution. Currently known only from the type locality, the Musgrave River, in central Area 11; elevation 100 – 200 m (Fig. 502).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	description	(Figs. 151, 153, 498)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	materials_examined	Type Material. Holotype (male): Gulf Province: Marawaka, near Ande, elev. 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (ZSM). Paratype: Same data as holotype (1 male ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	diagnosis	Differential Diagnosis. Similar to H. austrobesa in body proportions and the coarse and dense dorsal punctation (Figs. 150, 151); differing therefrom by the pronotal sides not emarginate between the anterior angle and the widest part, the less evident microreticulation of the head and pronotum, and the slightly smaller size (ca. 1.36 mm vs. 1.43). The metaventral plaques are quite similar in the two species. The male genitalia of the two species differ distinctively; reliable determinations will require dissections (Figs. 152, 153).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.36 / 0.59; head 0.20 / 0.35; pronotum 0.35 / 0.48, PA 0.37, PB 0.41; elytra 0.84 / 0.59. Dorsum dark brown to piceous; legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices microreticulate, dull, narrow walls to 1 xpd. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum shining, sparsely finely punctulate, each puncture with conspicuous seta; postmentum microreticulate medially, punctate and shining anteriorly and laterally. Genae raised, shining, without posterior ridge. Pronotum moderately transverse (PL / PW ca. 0.73), ca. median 3 / 5 of anterior margin slightly emarginate; coarsely, densely punctate, punctures on disc ca. 3 xpd frons punctures, interstices on disc shining, 1 – 2 xpd, interstices microreticulate and dull in impressions, punctures denser at anterior and posterior; PF 1 shallow, obsolete; PF 2 shallow; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 6 / 4. P 1 laminate; median carina sinuate in profile. P 2 narrow, raised slightly, l / w ca. 3 / 1, sides slightly diverging toward apex. Rim of mesocoxal cavity produced as very short carina on metaventrite. Plaques very narrow, weakly raised, converging slightly anteriorly, at sides of median depression that does not continue to P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 2 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, widest at about distal 1 / 3. Mesotibia straight, lateral margin slightly arcuate and bearing contiguous row of short stout spines. Metatibia straight, very slightly widened, widest at about distal 1 / 3. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 153).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	etymology	Etymology. Named in reference to being found at the border of Area 1 and Area 13, and placement in the Spinobesa group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3DFFCAFF79F14AFBC1FE1E.taxon	distribution	Distribution. Currently known only from the type locality, Marawaka near Ande, at an elevation of 1000 m (Fig. 498). This is in the eastern extreme of Area 1, but also on the border with Area 13; based on the elevation (<1200 m) this species could be placed in either Area. As usual, more collecting is needed.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	description	(Figs. 154, 156, 497)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Clear stream, summit of Kassem Pass at forest level, 1450 m, 6 ° 18 ' S, 145 ° 52 ' E, 27 vii 1975, R. W. Hornabrook (NMNZ). Paratypes (5): Eastern Highlands Province: Same data as holotype (1 NMNZ); Western Highlands Province: Simbai, 1800 – 2000 m, 5 ° 14.276 ' S, 144 ° 28.741 ' E, 1 iii 2007, Kinibel (PNG 138) (4 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	diagnosis	Differential Diagnosis. Similar in dorsal sculpture to H. owenobesa (Figs. 146, 154); differentiated therefrom by the longer elytra with more acuminate apices (PL / EL ca. 0.32 vs. 0.37), the more transverse pronotum (PL / PW ca. 0.64 vs. 0.67), and the smaller metaventral plaques (ratios ca. 1 / 1 / 1 / 4 vs. 1 / 1 / 5 / 4). The aedeagi of the two species greatly differ (Figs. 148, 156).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.54 / 0.66; head 0.25 / 0.35; pronotum 0.32 / 0.50, PA 0.40, PB 0.42; elytra 0.99 / 0.66. Dorsum dark brown to piceous; legs brown; maxillary palpi light brown, tip not darker. Frons punctures ca. 1 xef, slightly larger and denser near eyes than medially; interstices microreticulate and dull laterally, effacedly microreticulate and weakly shining medially, 1 – 3 xpd. Clypeus microreticulate laterally, finely, sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum transverse (PL / PW ca. 0.64), ca. median 3 / 5 of anterior margin very slightly emarginate; coarsely, densely punctate, punctures on disc ca. 3 xpd frons punctures, interstices on disc effacedly microreticulate, weakly shining, 1 – 2 xpd, interstices microreticulate and dull in impressions, punctures denser at anterior and posterior; PF 1 shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins narrow; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 1 / 4. P 1 laminate; median carina sinuate in profile. P 2 very narrow, raised slightly, l / w ca. 6 / 1, sides slightly converging toward apex. Plaques very small ovals, located basally at sides of median depression, depression does not continue anteriorly to tip of P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin ca. 5 xP 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest subapically, medial margin very slightly emarginate, lateral margin weakly arcuate and bearing short stout spines in widest part. Mesotibia straight, gradually increasing in width from base to apex, lateral margin bearing row of short stout spines. Metatibia straight, gradually increasing in width from base to apex, medial margin with few moderately long setae in distal 1 / 3, lateral margin with some short spines in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 156).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	etymology	Etymology. Named in reference to the very transverse prothorax.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3CFFCAFF79F3F1FDC9F8DD.taxon	distribution	Distribution. Currently known from two localities in the eastern part of Area 1, very near the border with Area 2; elevation range 1450 – 2000 m (Fig. 497).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	description	(Figs. 155, 157, 500)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	diagnosis	Differential Diagnosis. The coarse and dense dorsal punctation is similar to, though even coarser than, that of H. austrobesa and H. limbobesa (Figs. 150, 151, 155). In addition to the coarser punctation, H. perpunctata additionally differs from the compared species by the more angulate sides of the pronotum, the wider explanate margin of the elytra, and the narrower and more widely separated metavental plaques (ratios ca. 6 / 1 / 4 / 10). The aedeagus of H. perpunctata (Fig. 157) is abundantly distinct from that of other members of the Spinobesa group, and perhaps represents a separate species group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.37 / 0.71; head 0.25 / 0.37; pronotum 0.38 / 0.52, PA 0.41, PB 0.41; elytra 0.87 / 0.71. Dorsum of head piceous; pronotum light brown to testaceous in front of and behind piceous fascia with ill-defined margins, ratios of color bands, as measured in midline, ca. 7 / 12 / 6; elytra and legs brown; maxillary palpi light brown to testaceous, tip not darker. Frons coarsely densely punctate, punctures ca. 3 – 4 xef, slightly larger and denser near eyes than medially; interstices microreticulate and dull laterally, effacedly microreticulate and weakly shining medially, narrow walls to 1 xpd. Clypeus microreticulate laterally, moderately coarsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum moderately transverse (PL / PW ca. 0.73), ca. median 3 / 5 of anterior margin slightly emarginate; very coarsely, densely punctate, punctures on disc ca. 3 xpd frons punctures, interstices on disc shining, narrow walls to 1 xpd, punctures larger and denser at anterior and posterior; PF 1 shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 4 / 10. P 1 laminate; median carina sinuate in profile. P 2 very narrow, raised slightly, l / w ca. 2 / 1, sides slightly converging toward apex. Plaques minute, widely separated, carinate lines at sides of median depression that continues shallowly to tip of P 2. Metaventrite without midlongitudinal ridge. AIS width at straight posterior margin slightly wider than P 2. All legs rather short, femora moderately robust. Profemur (male) without tubercle next to trochanter; protibia widest at distal 1 / 3 where produced on medial margin. Mesotibia straight, lateral margin slightly arcuate and bearing row of short stout spines. Metatibia missing in holotype. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus as illustrated (Fig. 157).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	etymology	Etymology. Named in reference to the very coarse dorsal punctation.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3FFFC9FF79F2BAFEEAFA74.taxon	distribution	Distribution. Currently known only from the type locality, Kojé Creek, in the eastern arm of Area 3; elevation 160 m (Fig. 500).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3EFFCFFF79F681FB79F87B.taxon	description	(Figs. 158, 160, 343 – 345, 503)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3EFFCFFF79F681FB79F87B.taxon	materials_examined	Type material. Holotype (male): Indonesia: Papua Province: Bime – Calab Gebiet Bime [labels: " IRIAN JAYA: 22.9.1993 Bime – Calab Gebiet Bime, 1400 m // ca. 140 ° 12 ' E 04 ° 20 ' S, leg. M. Balke (16) // HOLOTYPUS Hydraena cristatigena sp. n. des. Jäch & Díaz 2000 "] (NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3EFFCFFF79F681FB79F87B.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, quite similar in dorsal habitus to H. variopaca (Figs. 158, 159); differing therefrom by the slightly smaller size (ca. 1.81 vs. 1.88 mm) and the more narrowly spaced metaventral plaques. Males are additionally recognized by the slightly widened hind tibiae. The male genitalia of the two species differ in significant details, while in general shape suggest a rather close relationship (Figs. 160, 161). The metaventrite and leg chaetotaxy are illustrated with SEMs (Figs. 343 – 345).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3EFFCFFF79F681FB79F87B.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.80 / 0.81; head 0.29 / 0.44; pronotum 0.41 / 0.56, PA 0.48, PB 0.44; elytra 1.10 / 0.81. Dorsum brown to dark brown, head and pronotal disc slightly darker, palpi light brown, except distal 1 / 2 of last palpomere darker. Dorsum of head and pronotum densely punctulate, dull; punctures of frons disc and pronotal disc ca. 1 xef, interstices ca. 1 xpd or slightly larger; punctures of clypeus obsolete. Labrum apicomedially excised, free margins rounded on each side of excision, weakly upturned. Mentum sparsely punctate, dull; postmentum densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; all pronotal foveae moderately deep. Elytra dull, punctures 1 – 2 xpd of largest pronotal punctures, most punctures with three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 7 / 8. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, weakly raised, carinate, located at lateral margins of deep, median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 1.5 x P 2. Protibia (male) widened, medial surface rather flat; mesotibia simple; metatibia with medial surface slightly widened near midlength. Abdominal apex symmetrical. Aedeagus (Fig. 160) main piece with large distal lobe, in ventral aspect lobe apically pointed, with arcuate right side, left side with small indentation demarcating tiny lobe; left paramere small, not bilobed, setae in two clusters; right paramere sharply rounded apically; distal piece, in right lateral view, with knob-like lobe. The aedeagus of the holotype, and the spermatheca, have been illustrated by Jäch and Díaz (2000).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3EFFCFFF79F681FB79F87B.taxon	distribution	Distribution. Horizontally, a very widely distributed species with an equally wide vertical range of 20 – 2200 m. Specimens have been collected from Areas 1, 2, 3 (perhaps), 5, 7, and 11 (Fig. 503). Notably, this " common " species was not collected during the large rotenone study of Kojé Creek, in eastern Area 3; this locality is " surrounded " by other sites where this species has been collected. Additional material (826): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, ex gravel banks, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 a) (3 NHM); nr. Port Moresby, Sogeri Plateau, Musgrave River, river, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200) (13 NHM); Tapini, 870 m, 8 ° 20.511 ' S, 146 ° 59.824 ' E, 29 x 2007, Kinibel (PNG 161) (34 MCZ, NHM, NMW, PNG, ZSM); Eastern Highlands Province: below Yonki, 850 m, 6 ° 11.332 ' S, 146 ° 3.052 ' E, 4 iv 2006, Balke & Sagata (PNG 31) (99 MCZ, NHM, NMW, PNG, ZSM); Kami River, Goroka, Eastern Highlands, [GE est.] 2000 – 2200 m, 6 ° 5 ' S, 145 ° 23 ' E, 23 vii 1965, R. W. Hornabrook (2 NMNZ); Mjairasa, Okapa, ex stones in waterfall spray, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 17 iii 1965, R. W. Hornabrook (1 NMNZ); NE, Bena River, 1500 m, 6 ° 0 ' S, 145 ° 36 ' E, 30 viii 1971, J. Sedlacek (3 BPBM); Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (1 NHM); Okapa, on wet rocks above waterline, fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183 a) (6 NHM); Okapa, under stones in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 186) (1 NHM); same locality, 10 ii 1965, M. E. Bacchus (MEB 187) (6 NHM); Purosa Valley, nr. Okapa, on submerged stones, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 8 ii 1965, M. E. Bacchus (MEB 182 a) (2 NHM); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (1 NHM); Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (31 NHM); Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (3 ZSM); Madang Province: Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (22 NHM); Finisterre Mts., Naho River Valley, Damanti, ex gravel banks of very fast-running clear stream, 914 m, 5 ° 55 ' S, 145 ° 58 ' E, 11 x 1964, M. E. Bacchus (MEB 47) (10 NHM); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (37 MCZ, NHM, NMW, PNG, ZSM); Simbai area, 1200 m, 5 ° 13.389 ' S, 144 ° 37.285 ' E, 10 iii 2007, Kinibel (PNG 152) (13 MCZ, NHM, NMW, PNG, ZSM); Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (1 NMW); Lae, Umg. [= environs of] Gebensis, Gorogias River, [GE est.] 20 – 30 m, 6 ° 44 ' S, 147 ° 0 ' E, 14 vi 1979, W. G. Ullrich (2 MHNG); Sandaun Province: Mianmin, 670 m, 4 ° 53.329 ' S, 141 ° 35.263 ' E, 22 x 2008, S. Ibalim (PNG 189) (58 MCZ, NHM, NMW, PNG, ZSM); Mianmin [Miyanmin], [GE est.] 700 – 800 m, 4 ° 54 ' S, 141 ° 36 ' E, 19 – 21 v 1998, A. Riedel (272 NMW); Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (50 MCZ, NHM, NMW, PNG, ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (10 MCZ, NHM, NMW, PNG, ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (32 MCZ, NHM, NMW, PNG, ZSM); Ofektamin, 820 m, 5 ° 4.113 ' S, 141 ° 35.841 ' E, 17 x 2008, S. Ibalim (PNG 190) (43 MCZ, NHM, NMW, PNG, ZSM); S Mianmin, [GE est.] 900 – 1100 m, 4 ° 54 ' S, 141 ° 36 ' E, 20 v 1998, A. Riedel (2 NMW); S Mianmin, stream, 700 m, 4 ° 54 ' S, 141 ° 36 ' E, 19 v 1998, A. Riedel (41 NMW); Southern Highlands Province: Tari to Koroba, 1600 m, 5 ° 46.5 ' S, 142 ° 50 ' E, 15 v 2006, Balke (PNG 65) (9 MCZ, NHM, NMW, PNG, ZSM); Western Highlands Province: Sepik-Ramu Basin, Inonake Stream, runs and small rapids among boulders, runs with cobbles, gravel and sand, partially shaded, 1320 m, 5 ° 40 ' S, 144 ° 42 ' E, 1 vii – 30 viii 1988, D. Dudgeon (18 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	description	(Figs. 159, 161, 342, 505)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (NHM). Paratypes (131): Eastern Highlands Province: Awande, Okapa, Eastern Highlands, [GE est.] 1500 – 1700 m, 6 ° 31 ' S, 145 ° 35 ' E, 25 v 1965, R. W. Hornabrook (3 NMNZ); Mjairasa, Okapa, ex stones in waterfall spray, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 17 iii 1965, R. W. Hornabrook (40 NMNZ); Okapa, ex muddy gravel banks of fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183) (2 NHM); Okapa, on logs and vegetable debris in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 187 a) (16 NHM); Okapa, on wet rocks above waterline, fast, clear stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 9 ii 1965, M. E. Bacchus (MEB 183 a) (13 NHM); Okapa, under stones in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 186) (12 NHM); same locality, 10 ii 1965, M. E. Bacchus (MEB 187) (26 NHM); Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (15 NHM); Gulf Province: Marawaka, near Ande, 1000 m, 7 ° 3.598 ' S, 145 ° 44.375 ' E, 10 xi 2006, Balke & Kinibel (PNG 89) (1 ZSM); Madang Province: Finisterre Mts., Naho River Valley, nr. Moro, ex gravel banks of small fast stream, 1432 m, 5 ° 50 ' S, 146 ° 7 ' E, 7 xi 1964, M. E. Bacchus (MEB 91) (3 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, quite similar in dorsal habitus to H. cristatigena (Figs. 158, 159); differing therefrom by the slightly larger size (ca. 1.88 vs. 1.81 mm), the slightly more widely spaced metaventral plaques, and the slightly coarser granulation of the elytra. Males are additionally recognized by the simple hind tibiae. The male genitalia of the two species differ in significant details, while in general shape suggest a rather close relationship (Figs. 160, 160). The ventral surfaces of the head and prothorax are illustrated with an SEM (Fig. 342).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.88 / 0.88; head 0.28 / 0.46; pronotum 0.43 / 0.58, PA 0.50, PB 0.48; elytra 1.17 / 0.88. Dorsum dark brown to piceous, head and pronotal disc slightly darker, palpi light brown, except distal 1 / 2 of last palpomere darker; legs brown, " knees " dark brown. Dorsum of head and pronotum densely punctulate, dull; punctures of frons disc and pronotal disc ca. 1 xef, interstices ca. 1 xpd or slightly larger; punctures of clypeus obsolete. Labrum apicomedially excised, free margins weakly upturned. Mentum sparsely punctate, effacedly microreticulate, weakly shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; all pronotal foveae moderately deep. Elytra subrugulose, dull, punctures very indistinct, most punctures with three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 10 / 7. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, weakly raised, subcarinate, located at lateral margins of deep, median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 1.5 x P 2. Protibia (male) markedly widened, slightly arcuate, medial surface rather flat; mesotibia simple; metatibia slender, gradually increasing in width from base to apex, very weakly emarginate on medial surface slightly before midlength. Abdominal apex symmetrical. Aedeagus (Fig. 161) main piece with large distal lobe, in ventral aspect lobe apically pointed, with arcuate right side and left side with tiny lobe; left paramere small, not bilobed, setae in two clusters; right paramere sharply rounded apically; distal piece, in right lateral view, with knob-like lobe.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	etymology	Etymology. Named in reference to the varyingly dull dorsum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B38FFCEFF79F2BAFEB8F8F8.taxon	distribution	Distribution. Currently known from far eastern Area 1 (1000 – 1700 m) and one locality in the Finisterre Mts., Area 5 (1432 m) (Fig. 505). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	description	(Figs. 162, 164, 340 – 341, 408, 504)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (NHM). Paratypes (152): Eastern Highlands Province: Mjairasa, Okapa, ex stones in waterfall spray, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 17 iii 1965, R. W. Hornabrook (1 NMNZ); Okapa, gravel banks of deep fast river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 189 a) (1 NHM); Okapa, on logs and vegetable debris in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 187 a) (5 NHM); Okapa, under stones in small river, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 186) (1 NHM); same locality, 10 ii 1965, M. E. Bacchus (MEB 187) (7 NHM); Umg. [= environs of] Igipinti, Korindaiop River, [GE est.] 600 – 1700 m, 6 ° 25 ' S, 145 ° 42 ' E, 18 vi 1979, W. G. Ullrich (22 MHNG); Umg. [= environs of] Okapa, [GE est.] 1500 – 1700 m, 6 ° 32 ' S, 145 ° 37 ' E, 18 vi 1979, W. G. Ullrich (2 MHNG); Waisa, nr. Okapa, in holes under stones in small fast river, 1524 m, 6 ° 38 ' S, 145 ° 32 ' E, 15 ii 1965, M. E. Bacchus (MEB 192 a) (14 NHM); Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (1 NHM); Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (2 NHM); Wanitabi Valley, nr. Okapa, on wet rocks above waterline in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 c) (14 NHM); Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (2 NHM); Finisterre Mts., Naho River Valley, Moro, small stream running into River Naho, ex crevices in vertical rock, heavy water flow, 1372 m, 5 ° 50 ' S, 146 ° 7 ' E, 2 xi 1964, M. E. Bacchus (MEB 80) (4 NHM); Morobe Province: ridge between Aseki – Menyamya, 2200 m, 7 ° 12 ' S, 146 ° 4 ' E, 12 iv 1998, A. Riedel (1 NMW); Western Highlands Province: Kundum, 1400 m, 5 ° 16.096 ' S, 144 ° 27.869 ' E, 3 iii 2007, Kinibel (PNG 142) (26 MCZ, NHM, NMW, PNG, ZSM); Sepik River Basin, Kil Stream, montane forest, 1800 m, 5 ° 40 ' S, 144 ° 42 ' E, 1 vii – 30 viii 1988, D. Dudgeon (2 NMW); Simbai, 1800 – 2000 m, 5 ° 14.276 ' S, 144 ° 28.741 ' E, 1 iii 2007, Kinibel (PNG 138) (11 MCZ, NHM, NMW, PNG, ZSM); Simbai, Kairong River, 1850 m, 5 ° 14.84 ' S, 144 ° 28.457 ' E, 2 iii 2007, Kinibel (PNG 139) (36 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group that lack micropunctulate ground sculpture of the head and pronotum, most similar to H. tritutela; differing therefrom by the smaller size (ca. 1.67 vs. 1.83 mm), the more truncate elytra, and the more discrete elytra serial punctures (Figs. 162, 163). In addition, the male hind tibiae are shaped differently in the two species. The male genitalia of the two species, while differing distinctively in several details, have a general shape that suggests relationship (figs. 164, 165). The maxillary palpi and metaventrite are illustrated with SEMs (Figs. 340 – 341).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.67 / 0.80; head 0.26 / 0.44; pronotum 0.42 / 0.58, PA 0.49, PB 0.46; elytra 1.00 / 0.80. Dorsum dark brown to piceous, head and pronotal disc slightly darker, palpi brown, except distal 1 / 2 of last palpomere slightly darker. Dorsum of head and pronotum densely punctate, interstices shining; punctures of frons disc and pronotal disc 1 – 2 xef, interstices ca. 1 xpd or slightly larger; punctures of clypeus distinct, smaller than punctures of frons. Labrum apicomedially excised, lobes rounded, free margins upturned. Mentum very finely, sparsely punctate, shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; all pronotal foveae moderately deep, PF 3 and PF 4 deeper than other foveae. Elytra weakly shining, serial punctures very discrete, 1 – 2 xpd of largest pronotal punctures, each puncture with three granules, one at anterior margin and one on each side. Intervals not raised, width 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 8 / 6. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, weakly raised, subcarinate, located at lateral margins of median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male), in ventral view, subapically on medial surface slightly widened and bearing few short stout setae, surface slightly but distinctly emarginate between widened part and; mesotibia slightly emarginate subapically on medial surface; metatibia markedly arcuate, medial surface flat or slightly concave, distal 1 / 3 distinctly widened and bearing short setal brush on upper surface. Abdominal apex symmetrical. Aedeagus (Fig. 164) main piece with small distal lobe, in ventral aspect apically produced in two small lobes; left paramere large, larger than distal lobe of main piece, markedly bilobed, each lobe with cluster of setae; right paramere very large, wide, apically rounded, in right lateral aspect arcuate toward ventral surface, setae in two clusters; distal piece with characteristic shape. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 408).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	etymology	Etymology. Named in honor of Mick Bacchus, who expertly collected more than 3,700 specimens used in this study.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3BFFCCFF79F2BAFDEAFD12.taxon	distribution	Distribution. Currently known from several localities in eastern Area 1 (1370 – 2200 m), and two localities in the Finisterre Mts., in Area 5 (1082 m) (Fig. 504). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422). Notes. In addition to the leg sexual dimorphism, the last maxillary palpomere is wider in males, and the pronotal foveae are slightly deeper in females.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	description	(Figs. 163, 165, 412, 512)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (NMW). Paratypes: Same data as holotype (79 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group that lack micropunctulate ground sculpture of the head and pronotum, most similar to H. bacchusi; differing therefrom by the larger size (ca. 1.83 vs. 1.67 mm), the more elongate elytra that are more sharply rounded apically and have larger granules on the serial punctures (Figs. 162, 163). In addition, the male hind tibiae are shaped differently in the two species. The male genitalia of the two species, while differing distinctively in several details, have a general shape that suggests relationship (Figs. 164, 165).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.83 / 0.81; head 0.29 / 0.46; pronotum 0.43 / 0.60, PA 0.48, PB 0.48; elytra 1.13 / 0.81. Dorsum very dark brown to piceous, palpi brown, except distal 1 / 2 of last palpomere slightly darker. Dorsum of head and pronotum densely punctate, interstices shining; punctures of frons disc and pronotal disc 1 – 2 xef, interstices varying, 0.5 – 2 xpd, usually about 1 xpd; punctures of clypeus distinct, smaller than punctures of frons. Labrum apicomedially excised, lobes rounded, free margins slightly upturned. Mentum sparsely punctate, shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Anterior margin of pronotum very weakly emarginate over middle 1 / 2; all pronotal foveae moderately deep, PF 3 and PF 4 deeper than other foveae. Elytra weakly shining, punctures 1 – 2 xpd of largest pronotal punctures, each puncture with three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 0.5 – 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly, moderately sharply rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 1 / 7 / 6. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, posteriorly carinate, more widely separated posteriorly than anteriorly, non-arcuate, located at lateral margins of deep, median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male) widened, medial surface rather flat, emarginate in distal 1 / 3; mesotibia slightly emarginate on medial surface in distal 1 / 2; metatibia bent at about distal 1 / 3, in lateral view distinctly widened from about midlenth to apex, apical widened area with small brush of setae on upper rim. Abdominal apex symmetrical. Aedeagus (Fig. 165) main piece with small distal lobe, in ventral aspect apically produced in two small lobes; left paramere large, larger than distal lobe of main piece, markedly bilobed, each lobe with cluster of setae; right paramere large, widest in distal 1 / 2, apically rounded, in right lateral aspect markedly arcuate toward ventral surface, setae in two clusters; distal piece with characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	etymology	Etymology. " Three guards "; named in reference to the three granules around each elytral puncture.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B3AFFF3FF79F0FAFCBFFED6.taxon	distribution	Distribution. Currently known only from the type locality near Garaina Saureri, in the northwestern part of Area 7; elevation 1600 m (Fig. 512). Notes. In females the last maxillary palpomere is slightly smaller than in males, and the pronotal foveae, especially PF 3 and PF 4, are larger and deeper than in males.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	description	(Figs. 166, 168, 508)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 1200 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 110) (ZSM). Paratype: Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 2400 m, 5 ° 55.615 ' S, 145 ° 22.699 ' E, 23 xi 2006, Balke & Kinibel (PNG 107) (1 male ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. tritutela and H. bacchusi; differing therefrom by the larger size (ca. 2.17 vs. 1.83 and 1.67 mm), the more coarsely and densely punctate head and pronotum, and the much larger, non-carinate plaques (Figs. 162, 163, 166). The shapes of the male hind tibiae differ in the three species. The aedeagus of H. balkei, while being the most divergent of the Cristatigena group, has a right paramere shape that suggests relationship with the compared species (Figs. 164, 165, 168).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.17 / 0.99; head 0.35 / 0.53; pronotum 0.51 / 0.68, PA 0.58, PB 0.58; elytra 1.33 / 0.99. Dorsum piceous, legs dark brown, palpi brown, except distal 1 / 2 of last palpomere slightly darker. Dorsum of head and pronotum densely punctate, interstices shining; punctures of frons 1 xef or slightly larger, interstices 0.5 – 1 xpd, punctures of clypeus distinct, smaller than punctures of frons; pronotal punctures coarse and dense, 2 – 3 xpd of frons punctures, interstices narrow walls to ca. 1 xpd or slightly larger. Labrum apicomedially excised, lobes rounded, free margins upturned. Mentum sparsely punctate, effacedly microreticulate, moderately dull; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; all pronotal foveae deep, PF 1 shallowly confluent with PF 3, PF 2 ' s shallowly confluent with one another in middle, PF 3 and PF 4 deeper than other foveae. Elytra dull, punctures slightly larger than largest pronotal punctures, each puncture with minute seta and three granules, one at anterior margin and one on each side. Intervals not raised, width 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 11 / 1.7. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2.5 / 1, sides parallel, apex blunt. Plaques wide, weakly raised, diverging slightly from anterior to posterior, located at lateral margins of deep, median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 1.5 x P 2. Protibia (male) gradually, moderately widening from base to apex, in dorsal view medial surface weakly emarginate in distal 1 / 2; mesotibia simple; metatibia in lateral view markedly widened in distal 1 / 2, medial surface of widened area flat or concave, bearing brush of short setae. Abdominal apex symmetrical. Aedeagus (Fig. 168) main piece slightly twisted clockwise compared with basal ring; left paramere moderately large, produced as lobe on ventral margin, setae in two clusters; right paramere long, widest in distal 1 / 2, apically rounded, in right lateral aspect markedly arcuate toward ventral surface, setae in two clusters; distal piece large, with characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	etymology	Etymology. Named in honor of the collector, Michael Balke, who has added so much to the knowledge of PNG water beetles.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B05FFF3FF79F3B9FE43F805.taxon	distribution	Distribution. Currently known from two very narrowly separated localities in northeastern Area 1; elevations 1200 m and 2400 m (Fig. 508).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	description	(Figs. 167, 169, 511)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	materials_examined	Type Material. Holotype (male): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, river, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200) (NHM). Paratypes (21): Sandaun Province: Mianmin, 670 m, 4 ° 53.329 ' S, 141 ° 35.263 ' E, 22 x 2008, S. Ibalim (PNG 189) (1 ZSM); Mianmin [Miyanmin], [GE est.] 700 – 800 m, 4 ° 54 ' S, 141 ° 36 ' E, 19 – 21 v 1998, A. Riedel (3 NMW); Mianmin, pool, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 193) (1 ZSM); Mianmin, river, 700 m, 4 ° 52.858 ' S, 141 ° 31.706 ' E, 21 x 2008, S. Ibalim (PNG 197) (5 ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (6 MCZ, NHM, NMW, PNG, ZSM); Ofektamin, 820 m, 5 ° 4.113 ' S, 141 ° 35.841 ' E, 17 x 2008, S. Ibalim (PNG 190) (4 ZSM); S Mianmin, stream, 700 m, 4 ° 54 ' S, 141 ° 36 ' E, 19 v 1998, A. Riedel (1 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, similar to H. inplacopaca and H. transvallis in the absence of metaventral plaques; differing from H. inplacopaca in the smaller size (ca. 1.62 vs. 2.07 mm), the less dense but slightly coarser pronotal punctation, and the less apparent dorsal setae; differing from H. transvallis by the larger elytral granules and the simple mesotibiae (Figs. 167, 170, 171). Males are differentiated from all other members of the Cristatigena group by the distinctively modified labrum. The male genitalia of the three species share a basic form, but differ in several significant details (Figs. 169, 172, 173).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.62 / 0.73; head 0.26 / 0.40; pronotum 0.37 / 0.51, PA 0.46, PB 0.43; elytra 0.98 / 0.73. Dorsum dark brown, head and pronotal disc piceous, palpi light brown, except distal 1 / 2 of last palpomere darker. Dorsum of head and pronotum densely punctulate, dull; punctures of frons disc and pronotal disc ca. 1 xef, interstices ca. 1 xpd or slightly larger; punctures of clypeus obsolete. Labrum wide but short, lateral angles sharply rounded, anterior margin angulate and with small point on each side of deep V-shaped apicomedian excision, free margins moderately upturned. Mentum sparsely, moderately coarsely punctate, weakly shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; all pronotal foveae moderately deep; PF 2 very narrowly separated from one another. Elytra subrugulose, dull, punctures very indistinct, each puncture with three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Metaventrite markedly tumid on each side of median impression, plaques absent, hydrofuge pubescence dense. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. No midlongitudinal carina between mesoventral intercoxal process and median impression. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male) widened, weakly arcuate, medial surface flat; mesotibia simple; metatibia very gradually widening from base to apex, very weakly arcuate. Abdominal apex symmetrical. Aedeagus (Fig. 169) main piece with comparatively small (for group) distal lobe, in ventral aspect, arching from right side toward left side, apically with two small rounded lobes; left paramere as large as distal lobe, widest at midlength, with two small lobes, each with a cluster of setae; right paramere longer than and apically slightly wider than distal lobe of main piece; distal piece, in right lateral view, with large lobe of characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	etymology	Etymology. Named in reference to the sexually dimorphic labrum, and the relationship to H. variopaca.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B04FFF2FF79F2BAFDD1F8F9.taxon	distribution	Distribution. An unusual, very disjunct distribution: several narrowly separated localities near Mianmin, in far western Area 1 (700 – 1080 m), and one locality far south, near Port Moresby, in Area 11 (100 – 200 m) (Fig. 511). Notes. Males from Mianmin, Sandaun Province: differ from the holotype in the following characters: the labrum is shaped very slightly differently; the metatibiae have a slightly more pronounced increase in width in the distal 1 / 2, and a slightly deeper emargination on the medial margin, just before the enlargement; the right paramere of the aedeagus is apically more truncate.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	description	(Figs. 170, 172, 509)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Waisa, nr. Okapa, in holes in partly burnt and decayed logs in small fast river, 1524 m, 6 ° 38 ' S, 145 ° 32 ' E, 15 ii 1965, M. E. Bacchus (MEB 192) (NHM). Paratypes: Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex muddy gravel banks of small shaded stream, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 177 a) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, similar to H. labropaca and H. transvallis in the absence of metaventral plaques; differing from both species in the larger size (ca. 2.07 vs. 1.62 and 1.68 mm), the less dense and slightly finer pronotal punctation, and the more apparent dorsal setae (Figs. 167, 170, 171). Males additionally differ from H. transvallis by the simple mesotibiae, and from H. labropaca by the differently shaped labrum; differing from both species by the metafemur, having the basal 1 / 2 of the lower surface slightly emarginate and bearing a moderately dense patch of short, arcuate setae. The male genitalia of the three species share a basic form, but differ in several significant details (Figs. 169, 172, 173).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.07 / 0.90; head 0.34 / 0.50; pronotum 0.49 / 0.66, PA 0.56, PB 0.54; elytra 1.23 / 0.90. Dorsum brown to dark brown, head and pronotal disc slightly darker, palpi light brown, except distal 1 / 2 of last palpomere darker. Dorsum of head and pronotum densely punctulate, dull; punctures of frons disc and pronotal disc ca. 1 xef, interstices ca. 1 xpd or slightly larger, each puncture with short fine seta; punctures of clypeus obsolete. Labrum apicomedially excised, free margins weakly upturned. Mentum finely, moderately densely punctate, shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; emargination with very narrow hyaline margin; pronotal foveae PF 1 and PF 2 moderately deep, PF 3 and PF 4 very deep. Elytra dull, punctures much larger and deeper than largest pronotal punctures, each puncture with short fine seta and three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Metaventrite markedly tumid on each side of median impression, plaques absent, hydrofuge pubescence dense. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides diverging very slightly to blunt apex. No midlongitudinal carina between mesoventral intercoxal process and median impression. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male) widened, weakly arcuate, medial surface flat or slightly concave; mesotibia simple; metafemur basal 1 / 2 of lower surface slightly emarginate and bearing moderately dense patch of short, arcuate setae; metatibia very gradually widening from base to apex, medial surface very slightly arcuate near midlength. Abdominal apex symmetrical. Aedeagus (Fig. 172) main piece with large distal lobe, in ventral aspect, weakly arching from right side toward left side, apically rounded, small lobe on left side; left paramere smaller than distal lobe, widest at midlength, with two small lobes, each with a cluster of setae; right paramere longer than and apically slightly narrower than distal lobe of main piece, apically blunt; distal piece, in right lateral view, with large lobe of characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	etymology	Etymology. Named in reference to the lack of metaventral plaques, and dull dorsal sculpture.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF1FF79F2BAFE7CF9D9.taxon	distribution	Distribution. Currently known from two localities near Okapa, in the eastern part of Area 1; both of which are at about 1524 m (Fig. 509).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	description	(Figs. 171, 173, 506)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 2 – 7 x 1964, M. E. Bacchus (MEB 30) (NHM). Paratype: Simbu Province: NE, Karimui, south of Goroka, 1000 m, 6 ° 30 ' S, 144 ° 51 ' E, 5 vi 1961, J. L. & M. Gressitt (1 BPBM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, similar to H. inplacopaca and H. labropaca in the absence of metaventral plaques; differing from H. inplacopaca in the smaller size (ca. 1.68 vs. 2.07 mm), the less dense and slightly coarser pronotal punctation, and the less apparent dorsal setae (Figs. 167, 170, 171). Males of H. transvallis are differentiated from both species by the widened mesotibiae; and from H. labropaca by the differently shaped labrum. The male genitalia of the three species share a basic form, but differ in several significant details (Figs. 169, 172, 173).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.68 / 0.78; head 0.25 / 0.44; pronotum 0.41 / 0.57, PA 0.49, PB 0.48; elytra 1.04 / 0.78. Dorsum brown to dark brown, head and pronotal disc slightly darker, palpi light brown, except distal 1 / 2 of last palpomere darker. Dorsum of head and pronotum densely punctulate, dull; punctures of frons disc and pronotal disc ca. 1 xef, interstices ca. 1 xpd or slightly larger, each puncture with short fine seta; punctures of clypeus obsolete. Labrum apicomedially with deep V-shaped notch, anterior margin at sides of notch with tiny point, free margins very weakly upturned. Mentum finely, moderately densely punctate, shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2; emargination with very narrow hyaline margin; pronotal foveae PF 1 and PF 2 moderately deep, PF 3 and PF 4 very deep. Elytra dull, punctures ca. 1 xpd or slightly larger than largest pronotal punctures, each puncture with short fine seta and three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin well developed, about as wide as widest part of metatibia. Metaventrite markedly tumid on each side of median impression, plaques absent, hydrofuge pubescence dense. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. No midlongitudinal carina between mesoventral intercoxal process and median impression. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male) widened, weakly arcuate, medial surface flat; mesotibia widened, widest part, slightly past midlength, wider than metatibia; metatibia very gradually widening from base to apex, very weakly arcuate. Abdominal apex symmetrical. Aedeagus (Fig. 173) main piece with large distal lobe, in ventral aspect, weakly arching from right side toward left side, apically rounded, small lobe on left side; left paramere smaller than distal lobe, widest at midlength, with two small lobes, each with a cluster of setae; right paramere longer than and apically slightly narrower than distal lobe of main piece, apically blunt; distal piece, in right lateral view, with large lobe of characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	etymology	Etymology. Named in reference to the geographical distribution, two localities separated by extensive lowlands.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B07FFF0FF79F48FFBE3FA9A.taxon	distribution	Distribution. Currently known from one locality in the southeastern part of Area 1, at the border with Area 13 (1000 m), and one locality in the Finisterre Mts., Area 5 at the border with Area 3 (1082 m) (Fig. 506). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	description	(Figs. 174, 176, 510)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (ZSM). Paratypes (14): Madang Province: Same data as holotype (8 MCZ, NHM, NMW, PNG, ZSM); Keki – Sewan, Adelbert Mts., 300 m, 4 ° 40.558 ' S, 145 ° 27.187 ' E, 30 xi 2006, Binatang Boys (PNG 121) (6 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	diagnosis	Differential Diagnosis. Readily differentiated from other members of the Cristatigena group by the combination of small size (ca. 1.39 mm) and the color, having a dark brown pronotal fascia that is bordered anteriorly and posteriorly by testaceous (Fig. 174); also differing from the other members of the species group by the short, oval elytra and the non-sexually dimorphic hind legs. The aedeagus has some superficial similarity to that of H. cristatigena (Figs. 160, 176).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.39 / 0.73; head 0.21 / 0.39; pronotum 0.35 / 0.50, PA 0.43, PB 0.40; elytra 0.43 / 0.40. Head dark brown to piceous; pronotum with large fascia, dark brown on disc, light brown laterally, testaceous transverse borders anterior and posterior to fascia; elytra brown, except explanate margin light brown or testaceous; legs light brown; palpi light brown, except distal 1 / 2 of last palpomere slightly darker. Dorsum of head and pronotum densely punctulate, dull; pronotal disc subrugulose; punctures of frons disc and pronotal disc ca. 1 xef, interstices narrow walls to ca. 1 xpd; punctures of clypeus obsolete. Labrum apicomedially excised, lobes rounded, free margins weakly upturned. Mentum sparsely punctate, shining; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin weakly emarginate over middle 1 / 2, emargination with very narrow hyaline border; pronotal foveae on disc moderately deep, PF 2 ' s shallowly confluent with one another in middle; PF 3 and PF 4 much deeper than PF 1 and PF 2. Elytra quite oval, dull, punctures ca. 1 xpd of largest pronotal punctures, each with minute seta and three granules, one at anterior margin and one on each side. Intervals not raised, width ca. 1 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another. Explanate margin wide, wider than widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1 / 4 / 5. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, weakly raised, located at lateral margins of median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 1.5 x P 2. Protibia (male) widened, medial surface very flat; mesotibia simple; metatibia slender, gradually widening from base to apex, straight or nearly imperceptibly arcuate. Abdominal apex symmetrical. Aedeagus (Fig. 176) main piece with large distal lobe, in ventral aspect lobe apically sharply rounded, medial margin broadly rounded; left paramere moderately sized, constricted at midlength, not bilobed, setae in two clusters; right paramere markedly constricted before midlength, apical part somewhat spearhead shaped; distal piece, in right lateral view, with characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	etymology	Etymology. Named in reference to the pronotal fascia and dull dorsum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B06FFF7FF79F778FCBCFC32.taxon	distribution	Distribution. Currently known only from two very narrowly separated localities in the Adelbert Mts., in northwestern Area 5; elevations 300 m and 400 m (Fig. 510).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	description	(Figs. 175, 177, 507)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: ridge between Aseki – Menyamya, 2200 m, 7 ° 12 ' S, 146 ° 4 ' E, 12 iv 1998, A. Riedel (NMW). Paratypes (11): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 2400 m, 5 ° 55.615 ' S, 145 ° 22.699 ' E, 23 xi 2006, Balke & Kinibel (PNG 107) (3 ZSM); Morobe Province: Same data as holotype (7 NMW); Western Highlands Province: Sepik River Basin, Waré Creek, partially shaded montane stream with angular, moss – covered boulders, small waterfalls and pools, 2000 m, 5 ° 42 ' S, 144 ° 39 ' E, 1 vii – 30 viii 1988, D. Dudgeon (1 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	diagnosis	Differential Diagnosis. Among members of the Cristatigena group, recognized by the combination of the confluent pronotal foveae PF 2, the coarsely punctate pronotum, the sharply rounded elytral apices, and the comparatively narrow explanate elytral margin. Somewhat similar in dorsal habitus to H. tritutela; differing therefrom by the effacedly micropunctulate ground sculpture of the head and pronotum, the confluent PF 2 foveae, the much more finely granulate elytra, and, in males, the differently shaped hind tibiae (Figs. 163, 167). The aedeagus of H. tibiopaca differs distinctively from that of other members of the Cristatigena group (Fig. 177).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.75 / 0.76; head 0.28 / 0.43; pronotum 0.41 / 0.57, PA 0.46, PB 0.47; elytra 1.07 / 0.76. Dorsum dark brown to piceous, palpi light brown, except distal 1 / 3 of last palpomere darker. Dorsum of head and pronotum effacedly punctulate, dull in impressions, weakly shining on reliefs; punctures of frons disc ca. 1 xef, on pronotal disc ca. 2 xef, interstices ca. 1 xpd or slightly larger; punctures of clypeus smaller than those of frons. Labrum apicomedially excised, lobes rounded, free margins weakly upturned. Last maxillary palpomere (male) with slightly sinuate lateral margin. Mentum sparsely punctate, dull; postmentum anterior 1 / 2 with punctation similar to mentum, posterior 1 / 2 densely micropunctulate. Genae raised, posterior ridge strong. Pronotum with anterior margin very weakly emarginate over middle 1 / 2; PF 1 with median posterior extension, almost confluent with transverse fovea formed by confluent PF 2; PF 3 and PF 4 very deep. Elytra moderately shining, punctures small, ca. 1 xpd of largest pronotal punctures, each with very short seta, some with very minute granule at base of seta on anterior margin of puncture, most punctures without perceptible granules at sides of punctures. Intervals not raised, width ca. 2 – 3 xpd, interstices between punctures of a row ca. 1 – 2 xpd. Apices in dorsal aspect conjointly, rather sharply rounded, in posterior aspect margins forming minute angle with one another. Explanate margin moderately developed, slightly narrower than widest part of metatibia. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 7 / 6. P 1 laminate; median carina sinuate in profile. P 2 moderately narrow, l / w ca. 2 / 1, sides parallel, apex blunt. Plaques very narrow, posteriorly carinate, more widely separated posteriorly than anteriorly, not arcuate, located at lateral margins of deep, median depression. Metaventrite tumid lateral to plaques. No midlongitudinal carina between mesoventral intercoxal process and plaques. Hydrofuge pubescence dense. AIS flat, width at straight posterior margin ca. 2 x P 2. Protibia (male) in lateral view gradually slightly widened from base to apex, in ventral view medial surface notched subapically, few short stout spine-like setae at base of notch; mesotibia simple; metatibia slender in ventral view, in lateral view markedly widened in distal 1 / 3, widened area concave on medial surface, upper rim with brush of short setae. Abdominal apex symmetrical. Aedeagus (Fig. 177) long compared with other members of group, main piece with large distal lobe, in ventral aspect, arching from right side toward left side, apically produced as sharply rounded lobe on left side; left paramere as long as and apically about as wide as distal lobe, widest apically, with two small lobes, each with a cluster of setae; right paramere slightly longer than and subapically slightly narrower than distal lobe of main piece, widest at about distal 2 / 3, apex sharply rounded; distal piece with large lobe of characteristic shape.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	etymology	Etymology. Named in reference to the modified hind tibiae of males, and the dull dorsal sculpture.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B01FFF6FF79F1DAFE9DFCA1.taxon	distribution	Distribution. Currently known from three localities in the eastern part of Area 1; elevation range 2000 – 2400 m (Fig. 507).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	description	(Figs. 178, 180, 346 – 348, 409, 515, 516)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	materials_examined	Type Material. Holotype (male): Queensland [labels: Queensland Blackb's Coll // luridipennis, Macl. // I 8298 Hydraena luridipennis Macl Queensland // // Hydraena impercepta Zwick spec. nov. Holotypus male design. P. Zwick 1975 // DIGITAL IMAGE captured 2004 P. D. Perkins] (SAMA).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	diagnosis	Differential Diagnosis. Differentiated from H. cavifrons by the non-concave frons and the comparatively small metaventral plaques, which are small ovals (SEM Fig. 346). The plaques are similar to those of H. buloba; differentiated from that species by the very differently shaped pronotum that has much less angulate sides, and is less transverse (PL / PW ca. 0.73 vs. 0.50), the less robust body, and the non-striate-impressed elytral series (Figs. 178, 179, 182). The pro- and metatibiae of males differ in all three species of the Luridipennis group in PNG, and the male genitalia distinctively differ (Figs. 180, 181, 184). The metaventrite, abdominal apex, and complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 346 – 348).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.00 / 0.88; head 0.25 / 0.45; pronotum 0.49 / 0.64, PA 0.49, PB 0.59; elytra 1.29 / 0.88. Head and large pronotal macula dark brown, remainder of dorsum, legs and maxillary palpi brown. Frons punctures ca. 1 xef; interstices narrow walls near eyes, 1 – 3 xpd medially. Clypeus microreticulate laterally, finely punctate medially. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotum densely coarsely punctate, punctures on disc deep, ca. 3 xpd those of frons, interstices narrow walls to 1 xpd, some interstices uniting to form short longitudinal lines; PF 1 absent; PF 2 shallow; PF 3 and PF 4 moderately deep, shallowly joined. Elytral punctures about 0.5 xpd of largest pronotal punctures. Intervals not raised, width ca. 1 xpd, interstices between punctures of a row slightly less. Apices in dorsal aspect separately rounded, in posterior aspect margins forming angle with one another. Metaventral disc densely punctate beneath hydrofuge pubescence, without plaques, median impression deep, longitudinal, subtriangular, basally ca. 2 x P 2. P 1 laminate; median carina angulate in profile. P 2 moderately narrow, l / w ca. 5 / 3, sides parallel, apex rounded. Very low midlongitudinal carina between mesoventral intercoxal process and median depression. AIS flat, width at arcuate posterior margin 2 x P 2. Abdominal apex with short setae; last tergite with depression on ventral face. Protibia with subapical angulation on inner surface. Mesotibia slender. Metatibia with rounded enlargement on inner surface near midlength, then tapering to apex; outer surface arcuate at base, then straight to apex. Aedeagus (Fig. 178) main piece slightly wider in lateral than ventral view, with large, strong process on right side of apical part, medial margin with two points; left paramere large, with four groups of setae; right paramere narrow, with three groups of setae. Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 409); tergite X with row of stout setae, tips blunt and angled ventrad.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	distribution	Distribution. In PNG, known from lowland Areas 3, 11, and 15; elevation range 20 – 305 m (Fig. 516). Also known from Australia, having a wide distribution pattern in Queensland and northern Northern Territory (Fig. 515).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	discussion	Remarks. In females the elytral apices are slightly more sharply rounded, the posterior declivity is not as abrupt, and the metaventral depression is not as deep as in males. Some specimens have the metaventral plaques apparent as very small, non-punctate ovals at the base of the median depression.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B00FFF4FF79F43FFD40FF42.taxon	materials_examined	Material Examined (92): Central Province: Loloki, 10 miles N of Port Moresby, ex gravel in roadside drain, [GE est.] 30 – 50 m, 9 ° 20 ' S, 147 ° 10 ' E, 19 iii 1965, M. E. Bacchus (MEB 209) (2 NHM); Loloki, 10 miles N of Port Moresby, ex swamp, much grass, [GE est.] 30 – 50 m, 9 ° 20 ' S, 147 ° 10 ' E, 19 iii 1965, M. E. Bacchus (MEB 208) (2 NHM); Moitaka, 7 miles N of Port Moresby, among vegetation hanging from bank into deep pool in field drain, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 205) (m # NHM); Moitaka, 7 miles N of Port Moresby, ex dead leaves in gravelly shallow of small pond, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 207) (4 NHM); Moitaka, 7 miles N of Port Moresby, ex shallow muddy margin of swamp, little weed, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 203) (1 NHM); Moitaka, 7 miles N of Port Moresby, ex weeds round margin of small pond, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 207 a) (1 NHM); Moitaka, 7 miles N of Port Moresby, shallow grassy margins of swamp, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 206) (19 NHM); Port Moresby – Brown River road, ex grassy shallows of large muddy pond, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 195) (30 NHM); Madang Province: 5 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 21 vi 1991, D. Larson (1 MCZ); Ramu Valley, 3 km N Brahman, [GE est.] 130 – 150 m, 5 ° 40 ' S, 145 ° 22 ' E, 16 v 1991, D. Larson (5 MCZ); Morobe Province: Markham Valley, Gusap, 90 miles NW of Lae, ex small muddy pools in almost dry stream bed, much algae, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 158) (1 NHM); Markham Valley, Gusap, 90 miles NW of Lae, small muddy pond, stony bottom, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 158) (1 NHM); Markham Valley, Gusap, c. 90 mi. W of Lae, ex cattle water troughs, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 3 xii 1964, M. E. Bacchus (MEB 114) (1 NHM); Markham Valley, Gusap, c. 90 miles NW of Lae, large pond, muddy bottom with thick layer of dead leaves, dense Ceratophyllum, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 162) (1 NHM); Markham Valley, Lae – Kainantu road, Erap River, ex gravel, [GE est.] 80 – 130 m, 6 ° 37 ' S, 146 ° 42 ' E, 26 i 1965, M. E. Bacchus (MEB 156) (1 NHM); Western (Fly) Province: Balimo, Om, [GE est.] 20 – 40 m, 8 ° 1.823 ' S, 142 ° 57.458 ' E, 9 – 11 xi 2008, Posman (PNG 185) (21 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	description	(Figs. 179, 181, 517)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, 4.5 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (MCZ). Paratypes (50): East Sepik Province: Sepik, main river, 20 m, 4 ° 12 ' S, 143 ° 36 ' E, 2 iii 1965, R. W. Hornabrook (5 NMNZ); Tambanum, main Sepik River, on flooded ground behind village, [GE est.] 5 – 20 m, 4 ° 12 ' S, 143 ° 36 ' E, 2 iii 1965, R. W. Hornabrook (17 NMNZ); Yentchan, main Sepik River, in small stream behind village, [GE est.] 20 – 50 m, 4 ° 8 ' S, 142 ° 55 ' E, 18 iii 1965, R. W. Hornabrook (14 NMNZ); Madang Province: Ramu Valley, 4.5 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (10 MCZ); Ramu Valley, Brahman Mission stock pond, [GE est.] 130 – 150 m, 5 ° 43 ' S, 145 ° 22 ' E, 17 iv 1991, D. Larson (4 MCZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	diagnosis	Differential Diagnosis. Recognized from the two other members of the Luridipennis group in PNG by the concave frons and the comparative large metaventral plaques (Fig. 179). Additionally differing from H. buloba by the differently shaped pronotum (PL / PW ca. 0.72 vs. 0.50), the less robust body, and the non-striate-impressed elytral series. The pro- and metatibiae of males differ in all three species, and the male genitalia distinctively differ (Figs. 180, 181, 184).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.19 / 0.88; head 0.36 / 0.46; pronotum 0.50 / 0.69, PA 0.51, PB 0.58; elytra 1.35 / 0.88. Dorsum of head and pronotal disc piceous, remainder of dorsum brown to dark brown; legs brown; maxillary palpi light brown to testaceous. Frons concave near eyes, punctures ca. 1 – 2 xef; interstices shining, 1 – 3 xpd. Clypeus laterally subrugulose, medially less coarsely punctate. Mentum anteriorly shining, moderately coarsely punctate, posteriorly slightly concave, rugulose, dull; postmentum coarsely punctate, interstices weakly shining. Genae raised, lacking posterior ridge, midlongitudinally with small fovea in front of and behind ridge. Pronotum densely coarsely punctate, punctures on disc deep, ca. 3 – 4 xpd those of frons, interstices narrow walls to 1 xpd; PF 1 shallow, in midline extended to ca. midlength of pronotum; PF 2 deep, oval, oblique; PF 3 and PF 4 deep, confluent. Elytral punctures not striate-impressed, ca. 1 xpd of largest pronotal punctures. Intervals shining, width ca. 1 – 2 xpd, interstices between punctures of a row less; third interval slightly raised, other intervals not raised. Explanate margin wide. Apices in dorsal aspect separately rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 1 / 1 / 4 / 2.5. P 1 laminate; median carina angulate in profile. P 2 very narrow, l / w ca. 7 / 2, sides parallel, apex blunt. Metaventral disc densely punctate beneath hydrofuge pubescence, plaques moderately large, widest posteriorly, tapering to point anteriorly, located basolaterally on sides of deep, inverted V-shaped median depression. Very short and low midlongitudinal ridge behind mesoventral intercoxal process. AIS flat, or nearly so, width at slightly arcuate posterior margin slightly greater than 3 x P 2. Abdominal apex asymmetrical, with short setae; last tergite notched on ventral face. Profemur with moderately large, sharply pointed tubercle on anterior margin near trochanter. Protrochanter very weakly keeled. Protibia slightly arcuate, distal 2 / 5 widened and forming ridge on medial margin, small tooth at base of ridge, same area with row of short, stout setae on ventral surface. Mesotibia straight. Metafemur with short, sparse setae on entire length of lower surface. Metatibia weakly arcuate, slender, dorsomedian margin with brush of sparse setae in distal 4 / 5. Aedeagus as illustrated (Fig. 181).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	etymology	Etymology. Named in reference to the concave frons.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B02FFF4FF79F30AFE7DF8DD.taxon	distribution	Distribution. A lowland species, with localities in both the western and eastern parts of Area 3; elevation range 20 – 150 m (Fig. 517).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	description	(Figs. 182, 184, 518)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex shallow pools in marsh, 1128 m, 6 ° 48 ' S, 146 ° 48 ' E, 8 i 1965, M. E. Bacchus (MEB 144) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	diagnosis	Differential Diagnosis. Recognized from the two other members of the Luridipennis group in PNG by the more robust body, the more markedly angulate sides of the very transverse pronotum (PL / PW ca. 0.50), and the striate-impressed elytral series (Figs. 178, 179, 182). The pro- and metatibiae of males differ in all three species, and the male genitalia distinctively differ (Figs. 180, 181, 184).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 2.20 / 0.98; head 0.30 / 0.48; pronotum 0.49 / 0.75, PA 0.55, PB 0.64; elytra 1.43 / 0.98. Dorsum of head and pronotal disc piceous, remainder of dorsum dark brown; legs and maxillary palpi brown. Frons punctures ca. 2 – 3 xef; interstices shining, narrow walls to 1 xpd. Clypeus laterally microreticulate and as coarsely punctate as frons, medially less coarsely punctate. Mentum shining, finely sparsely punctate; postmentum medially microreticulate, otherwise finely sparsely punctate, shining. Genae raised, lacking posterior ridge, midlongitudinally impressed. Pronotum densely coarsely punctate, punctures on disc deep, ca. 3 – 4 xpd those of frons, interstices narrow walls to 1 xpd, some interstices uniting to form short longitudinal lines; PF 1 shallow, in midline extended to ca. midlength of pronotum; PF 2 deep, oval, oblique; PF 3 and PF 4 deep, shallowly joined. Elytral punctures striate-impressed, ca. 1.5 xpd of largest pronotal punctures. Intervals slightly raised, width ca. 1 xpd, interstices between punctures of a row less, some punctures contiguous. Explanate margin wide. Apices in dorsal aspect separately rounded, in posterior aspect margins forming angle with one another. Metaventral disc densely punctate beneath hydrofuge pubescence, plaques very small, oval, located basolaterally on sides of deep, inverted V-shaped median depression. P 1 laminate; median carina angulate in profile. P 2 very narrow, l / w ca. 5 / 3, sides parallel, apex blunt. No carina between mesoventral intercoxal process and median depression. AIS flat, width at slightly arcuate posterior margin 3 x P 2. Abdominal apex asymmetrical, with short setae; last tergite notched on ventral face. Protrochanter weakly keeled. Protibia straight, slightly widened on medial margin at about distal 1 / 3. Mesotibia straight. Metafemur with brush of long setae on entire length of lower surface. Metatibia straight, medial margin slightly widened in distal 1 / 2, dorsomedian margin with brush of setae in distal 1 / 2. Aedeagus as illustrated (Fig. 184).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	etymology	Etymology. Named in reference to the large rounded lobes of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0DFFFBFF79F2BAFEB8FA9C.taxon	distribution	Distribution. Currently known only from the type locality in the Herzog Mts. of Area 6; elevation 1128 m (Fig. 518).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	description	(Figs. 183, 185, 534)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	materials_examined	Type Material. Holotype (male): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, ex gravel banks, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 a) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	diagnosis	Differential Diagnosis. Similar in color and dorsal sculpture to H. galea (Figs. 183, 186); differing therefrom by the slightly narrower body form (EW / TL ca. 0.40 vs. 0.45), the narrower mesoventral intercoxal process (P 2) (plaque ratios ca. 4 / 1 / 5 / 5 vs. 5 / 1 / 5 / 5), and the micropunctulate mentum. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 185, 188).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.36 / 0.55; head 0.23 / 0.31; pronotum 0.32 / 0.45, PA 0.35, PB 0.37; elytra 0.83 / 0.55. Dorsum of head with frons dark brown to reddish brown, clypeus slightly lighter, labrum testaceous; pronotum brown around ill-defined dark brown macula on disc; elytra dark brown to reddish brown; legs brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 5 / 5. P 1 ca. 1 / 2 P 2; median carina very low, bisinuate in profile. P 2 transversely concave, l / w ca. equal, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, anteriorly converging very slightly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.7 x P 2. All legs long and slender. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 185).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	etymology	Etymology. Named in reference to the relationship to H. pala, but the absence of the prosternal fovea (" pala ") present in that species.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFFAFF79F30AFE25F9BD.taxon	distribution	Distribution. Currently known only from the type locality, the Musgrave River, in central Area 11; elevation 100 – 200 m (Fig. 534).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFF9FF79F453FD59FBCE.taxon	description	(Figs. 186, 188, 523) Type Material. Holotype (male): Eastern Highlands Province: Akameku-Brahmin, Bismarck Range, 700 m, 5 ° 52.754 ' S, 145 ° 23.209 ' E, 24 xi 2006, Balke & Kinibel (PNG 109) (ZSM). Paratypes (2): Eastern Highlands Province: Sepik River Basin, stream beside milestone labelled G- 99, unshaded stream with angular boulders, some coated with java moss, 1540 m, 6 ° 18 ' S, 145 ° 55 ' E, 1 vii- 30 viii 1988, D. Dudgeon (2 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFF9FF79F453FD59FBCE.taxon	diagnosis	Differential Diagnosis. Similar in color and dorsal sculpture to H. impala (Figs. 183, 186); differing therefrom by the slightly wider body form (EW / TL ca. 0.45 vs. 0.40), the wider mesoventral intercoxal process (P 2) (plaque ratios ca. 5 / 1 / 5 / 5 vs. 4 / 1 / 5 / 5), and the non-micropunctulate mentum. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 185, 188).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFF9FF79F453FD59FBCE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.45 / 0.65; head 0.19 / 0.34; pronotum 0.35 / 0.49, PA 0.35, PB 0.38; elytra 0.92 / 0.65. Dorsum of head with frons dark brown to dark reddish brown, clypeus lighter, brown, labrum testaceous; pronotum brown around ill-defined dark reddish brown macula on disc; elytra dark brown to dark reddish brown; legs reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger and denser near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum microreticulate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures larger and denser at anterior and posterior; PF 1 and PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide in anterior 1 / 2; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 5 / 5. P 1 ca. 2 / 5 P 2; median carina bisinuate in profile. P 2 l / w ca. 4 / 5, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.4 x P 2. All legs moderately long and slender. Profemur (male) with small tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 188).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFF9FF79F453FD59FBCE.taxon	etymology	Etymology. Named in reference to the helmet shape of the distal piece of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0CFFF9FF79F453FD59FBCE.taxon	distribution	Distribution. Currently known from two localities at the border of the eastern parts of Areas 1 and 2, at very different elevations of 700 m and 1540 m (Figs. 523).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	description	(Figs. 187, 189, 519)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex gravel bank of shallow stream, 1082 m, 5 ° 55 ' S, 145 ° 58 ' E, 12 x 1964, M. E. Bacchus (MEB 49) (NHM). Paratypes (23): Eastern Highlands Province: Sepik River Basin, stream beside milestone labelled G- 99, unshaded stream with angular boulders, some coated with java moss, 1540 m, 6 ° 18 ' S, 145 ° 55 ' E, 1 vii – 30 viii 1988, D. Dudgeon (1 NMW); Madang Province: Same data as holotype (2 NHM); Finisterre Mts., Naho River Valley, Damanti, ex small pool, probably permanent, in clay in dense shade, 1067 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 39) (10 NHM); Morobe Province: Wau, Wau Ecology Institute, secondary montane rainforest, pan trap, 1200 m, 7 ° 20 ' S, 146 ° 43 ' E, 1 – 30 viii 1983, S. & P. Miller (10 BPBM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	diagnosis	Differential Diagnosis. Similar in size (ca. 1.37 – 1.39 mm), body proportions and color to H. exhalista (Figs. 187, 190). These two species have the anterior and posterior widths of the pronotum equal; in the other species in the Impala group the pronotum is slightly narrower anteriorly than at the base. Hydraena inhalista differs from H. exhalista in the slightly narrower body form (EW / TL ca. 0.43 vs. 0.45), the slightly coarser punctation on the frons disc, the non-concave mesoventral intercoxal process (P 2), and the slightly different plaque ratios (ca. 4 / 1 / 4 / 6 vs. 5 / 1 / 5 / 5). In addition, the male protibiae differ slightly in the two species. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 189, 192).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.37 / 0.59; head 0.21 / 0.33; pronotum 0.34 / 0.46, PA 0.36, PB 0.36; elytra 0.79 / 0.59. Dorsum of head with frons dark brown to reddish brown, clypeus slightly lighter, labrum testaceous; pronotum brown around ill-defined dark brown macula on disc; elytra dark brown to reddish brown; legs brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum micropunctulate, dull. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 4 / 6. P 1 ca. 1 / 2 P 2; median carina bisinuate in profile. P 2 l / w ca. equal, sides slightly diverging toward non-concave, blunt apex. Plaques short, very narrow, carinate, parallel, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS conjointly concave with anterior area of first ventrite, width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slen- der. Profemur (male) with tubercle next to trochanter; protibia very slightly arcuate, anterior margin very slightly widened subapically. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 189).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	etymology	Etymology. " Inhaler "; named in reference to the concavity between the metaventral plaques and on the first abdominal sternite, and to the expanded area between the mesocoxae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0FFFF8FF79F68CFECAFC5E.taxon	distribution	Distribution. Currently known from one locality in eastern Area 1 (1540 m), two very narrowly separated sites across the Markham Valley in the Finisterre Mts. of Area 5 (1067 m and 1082 m), and one locality in Area 6 (1540 m) (Fig. 519).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	description	(Figs. 190, 192, 524)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	materials_examined	Type Material. Holotype (male): Gulf Province: Marawaka, Mala, 1400 m, 7 ° 5.664 ' S, 145 ° 44.467 ' E, 11 xi 2006, Balke & Kinibel (PNG 90) (ZSM). Paratypes: Same data as holotype (3 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	diagnosis	Differential Diagnosis. Similar in size (ca. 1.37 – 1.39 mm), body proportions and color to H. inhalista (Figs. 187, 190). These two species have the anterior and posterior widths of the pronotum equal; in the other species in the Impala group the pronotum is slightly narrower anteriorly than at the base. Hydraena exhalista differs from H. inhalista in the slightly wider body form (EW / TL ca. 0.45 vs. 0.43), the finer punctation on the frons disc, the concave mesoventral intercoxal process (P 2), and the slightly different plaque ratios (ca. 5 / 1 / 5 / 5 vs. 4 / 1 / 4 / 6). In addition, the male protibiae differ slightly in the two species, with the distal enlargement wider in H. exhalista. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 189, 192).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.39 / 0.63; head 0.24 / 0.34; pronotum 0.34 / 0.47, PA 0.38, PB 0.38; elytra 0.83 / 0.64. Dorsum of head with frons dark reddish brown, clypeus lighter, brown, labrum testaceous; pronotum brown to light reddish brown; elytra dark brown to dark reddish brown; legs reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, much larger and denser near eyes than medially; interstices shining, on disc ca. 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum effacedly microreticulate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 0.5 xpd frons punctures, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 5 / 5. P 1 ca. 2 / 5 P 2; median carina bisinuate in profile. P 2 transversely slightly concave, l / w ca. equal, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, parallel or converging very slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin very slightly greater than P 2. All legs moderately long and slender. Profemur (male) with small tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 markedly widened on anterior margin, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) very deeply notched. Aedeagus as illustrated (Fig. 192).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	etymology	Etymology. Named in reference to relationship with H. inhalista, and the less concave mesoventrite.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0EFFFFFF79F63CFC32FD8E.taxon	distribution	Distribution. Currently known only from the type locality, Marawaka, Mala, in the extreme southeastern part of Area 1, at the border with Area 13; elevation 1400 m (Fig. 524).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	description	(Figs. 191, 193, 520)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Lower Naho Valley, Hinggia, ex rocks and gravel bank of swift clear stream, 762 m, 5 ° 50 ' S, 146 ° 7 ' E, 28 xi 1964, M. E. Bacchus (MEB 112) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	diagnosis	Differential Diagnosis. Similar in body proportions and dorsal sculpture to H. pacificica (Figs. 191, 194). These two species have the mesoventral intercoxal process (P 2) very short (length slightly less than the apical width), compared with the other species in the Impala group. Hydraena apertista differs from H. pacificica in the slightly less emarginate anterior margin of the pronotum, the different plaque ratios (ca. 6 / 1 / 5 / 7 vs. 4 / 1 / 4 / 5), and in general a more uniform dorsal coloration. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 193, 196).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.48 / 0.63; head 0.23 / 0.33; pronotum 0.33 / 0.47, PA 0.37, PB 0.38; elytra 0.88 / 0.63. Dorsum dark reddish brown, lateral areas of pronotum lighter than disc; legs brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum medially slightly concave and effacedly micropunctulate, otherwise finely sparsely punctate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins rather wide in anterior 1 / 2; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 5 / 7. P 1 ca. 1 / 2 P 2; median carina bisinuate in profile. P 2 raised, very short, length slightly less than apical width, sides slightly converging toward blunt apex. Plaques very narrow, carinate, converging very slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.7 x P 2. All legs moderately long and slender. Profemur (male) with small tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 widened anteriorly, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 193).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	etymology	Etymology. " Opener "; named in reference to the bottle-opener shape of the aedeagal process.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B09FFFFFF79F041FD31F804.taxon	distribution	Distribution. Currently known only from the type locality in the Finisterre Mts.; Area 5 but very near the bor- der with Area 3; elevation 762 m (Fig. 521).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	description	(Figs. 194, 196, 521)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Huon Peninsula, Kwapsanek, 850 m, 6 ° 34.913 ' S, 147 °. 526 ' E, 31 iii 2006, Balke & Sagata (PNG 25) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	diagnosis	Differential Diagnosis. Similar in body proportions and dorsal sculpture to H. apertista (Figs. 191, 194). These two species have the mesoventral intercoxal process (P 2) very short (length slightly less than the apical width), compared with the other species in the Impala group. Hydraena pacificica differs from H. apertista in the slightly more strongly emarginate anterior margin of the pronotum, the different plaque ratios (ca. 4 / 1 / 4 / 5 vs. 6 / 1 / 5 / 7), and in general a less uniform dorsal coloration, with an ill-defined pronotal macula. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 193, 196).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.31 / 0.58; head 0.22 / 0.30; pronotum 0.31 / 0.44, PA 0.34, PB 0.36; elytra 0.77 / 0.58. Dorsum of head with frons dark brown to dark reddish brown, clypeus lighter, brown, labrum testaceous; pronotum brown around ill-defined dark reddish brown macula on disc; elytra dark brown to dark reddish brown; legs reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; PF 1 and PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 4 / 5. P 1 ca. 1 / 2 P 2; median carina bisinuate in profile. P 2 very short, l / w ca. 3 / 4, sides slightly converging toward blunt apex. Plaques very narrow, carinate, converging very slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.7 x P 2. All legs moderately long and slender. Profemur (male) with very small tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) very deeply notched. Aedeagus as illustrated (Fig. 196).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	etymology	Etymology. Named in reference to the shape of the distal process of the aedeagus, which recalls the two-fingered universal peace (or victory) sign.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFEFF79F2BAFE1FF991.taxon	distribution	Distribution. Currently known only from the type locality in the Huon Peninsula, in southeastern Area 5; elevation 850 m (Fig. 521).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	description	(Figs. 195, 197, 526)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Umg. [= environs of] Kainantu, Onerunka, [GE est.] 1500 – 1700 m, 6 ° 17 ' S, 145 ° 52 ' E, 1 – 30 iii 1980, W. G. Ullrich (MHNG).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	diagnosis	Differential Diagnosis. Similar in color and dorsal sculpture to H. processa (Figs. 195, 198); differing therefrom by the larger size (TL ca. 1.63 vs. 1.48 mm), the slightly narrower body form (EW / TL ca. 0.44 vs. 0.47), the wider mesoventral intercoxal process (P 2), the more widely spaced plaques (plaque ratios ca. 6 / 1 / 5 / 8 vs. 5 / 1 / 5 / 7), and the confluently concave AIS and first abdominal ventrite. The general plan of the male genitalia of the two species also suggests a relationship, but the genitalia distinctively differ in details, and should be examined for reliable determinations (Figs. 197, 200).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.63 / 0.72; head 0.28 / 0.37; pronotum 0.38 / 0.52, PA 0.40, PB 0.44; elytra 0.97 / 0.72. Dorsum dark reddish brown, frons darkest, clypeus and labrum lightest; legs reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger and denser near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc slightly smaller than smallest frons punctures, interstices shining, 2 – 4 xpd, punctures larger and denser at anterior and posterior; disc slightly longitudinally convex; PF 1 very shallow, obsolete; PF 2 shallow, medially confluent, forming U-shaped impression; PF 3 deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 5 / 8. P 1 ca. 2 / 3 P 2; median carina bisinuate in profile. P 2 transversely slightly concave, l / w ca. 5 / 6, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS conjointly concave with anteromedial area of first ventrite, width at straight posterior margin ca. 1.3 x P 2. All legs moderately long and slender. Profemur (male) with small tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 197).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	etymology	Etymology. Named in reference to the confluently concave AIS and first abdominal ventrite.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B08FFFDFF79F477FD5FFBA2.taxon	distribution	Distribution. Currently known only from the type locality near Onerunka, in the eastern part of Area 1, where it borders Area 2; elevation 1500 – 1700 m (Fig. 526).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	description	(Figs. 198, 200, 410, 522)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex dead leaves in small stream in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 139) (NHM). Paratypes (70): Morobe Province: Same data as holotype (42 NHM); Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 9 i 1965, M. E. Bacchus (MEB 147 a) (20 NHM); NE, McAdam Park, [GE est.] 700 – 900 m, 7 ° 16 ' S, 146 ° 40 ' E, 29 viii 1968, J. Balogh (No. NG – W – B. 38) (8 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	diagnosis	Differential Diagnosis. Similar to H. bicarinova in body proportions and color (Figs. 198, 199). These two species are the broadest in the Impala group: the EW / TL ratio is ca. 0.48 for H. bicarinova and 0.47 for H. processa (the ratio varies from 0.40 to 0.48 in the group). Hydraena processa differs from H. bicarinova in the slightly coarser dorsal punctation, the deeper pronotal foveae PF 2, and the slightly narrower prosternal intercoxal process (plaque ratios ca. 5 / 1 / 5 / 7 vs. 6 / 1 / 5 / 7). The general plan of the male genitalia of the two species also suggests a relationship, and the genitalia should be examined for reliable determinations (Figs. 200, 201).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.48 / 0.69; head 0.20 / 0.35; pronotum 0.36 / 0.50, PA 0.38, PB 0.42; elytra 0.92 / 0.69. Dorsum of head with frons dark brown to dark reddish brown, clypeus lighter, brown, labrum testaceous; pronotum brown around ill-defined dark reddish brown macula on disc; elytra dark brown to reddish brown; legs reddish brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 2 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 5 / 7. P 1 ca. 2 / 3 P 2; median carina bisinuate in profile. P 2 transversely concave, length slightly less than width, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, parallel or very slightly converging anteriorly, at sides of very deep median depression. Metaventrite concave between P 2 and plaques, strong ridge extended from each coxal cavity. AIS width at straight posterior margin ca. equal P 2. All legs moderately long and slender. Profemur (male) with small tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 200). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 410).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	etymology	Etymology. Named in reference to the S-shaped process of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0BFFFCFF79F6AAFAC8FC82.taxon	distribution	Distribution. Currently known from two localities in Area 6; elevations 700 – 900 m and 1220 m (Fig. 522).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0AFFE3FF79F14FFEDCFF61.taxon	description	(Figs. 199, 201, 525)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0AFFE3FF79F14FFEDCFF61.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Wanitabi Valley, nr. Okapa, ex dead leaves caught among rocks in small swift river, 1372 m, 6 ° 32 ' S, 145 ° 37 ' E, 5 ii 1965, M. E. Bacchus (MEB 171 b) (NHM). Paratype: Same data as holotype (1 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0AFFE3FF79F14FFEDCFF61.taxon	diagnosis	Differential Diagnosis. Similar to H. processa in body proportions and color (Figs. 198, 199). These two species are the broadest in the Impala group: the EW / TL ratio is ca. 0.48 for H. bicarinova and 0.47 for H. processa (the ratio varies from 0.40 to 0.48 in the group). Hydraena bicarinova differs from H. processa in the slightly finer dorsal punctation, the shallower pronotal foveae PF 2, and the slightly wider prosternal intercoxal process (plaque ratios ca. 6 / 1 / 5 / 7 vs. 5 / 1 / 5 / 7). The general plan of the male genitalia of the two species also suggests a relationship, and the genitalia should be examined for reliable determinations (Figs. 200, 201).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0AFFE3FF79F14FFEDCFF61.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.46 / 0.70; head 0.21 / 0.35; pronotum 0.37 / 0.51, PA 0.39, PB 0.43; elytra 0.89 / 0.70. Dorsum and legs brown to dark reddish brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures very slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow, obsolete; PF 3 moderately deep; PF 4 very shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 5 / 7. P 1 ca. 1 / 2 P 2; median carina bisinuate in profile. P 2 transversely slightly concave, length slightly less than width, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging very slightly anteriorly, at sides of very deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slender. Profemur (male) with very small tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 widened anteriorly, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 210).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B0AFFE3FF79F14FFEDCFF61.taxon	etymology	Etymology. Named in reference to the carinate metaventral plaques and to the ovate body shape. Distribution. Currently known only from the type locality near Okapa, in the eastern part of Area 1; elevation 1372 m (Fig. 525).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE3FF79F361FB3DFA29.taxon	description	Some of the broadest species of PNG Hydraena are found in this group. The mesoventral intercoxal process (P 2) is comparatively wide and concave, and all of the species have widely separated, carinate plaques. The protibiae of males are modified, but not markedly so. The male genitalia have a similar basic plan, with a tendency for the left paramere to be rotated toward the dorsal surface of the aedeagus (e. g. Figs. 220, 221). Members of the Pala group are similar to members of the Impala group, but the latter have the midlongitudinal carina of the prosternum extending the entire length; therefore the posterior part is not concave. Although H. tritropis lacks the concave prosternal intercoxal area, the carina is straight, not bisinuate as in members of the Impala group; the form of the aedeagus of this species also supports its placement in the Pala group. The female tergite X, gonocoxite, and spermatheca of H. pala are illustrated (Fig. 411); as expected, they show some similarities (setal patterns, spermatheca shape) with those structures in the Impala group, but have a very differently shaped tergite X (Figs. 410, 411). Members of the Pala group have only been collected in lowland rain forest, at an elevation range of 160 – 400 m (maps Figs. 428, 527 – 533). Only the three following microhabitat descriptors are given in the locality records: " ex. gravel banks "; " unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter "; " river. " Five species in the Pala group were collected from Kojé Creek in Area 3. In fact, four species in the group are only known from that site (Fig. 528). These collections were made during a large rotenone study (Dudgeon 1990, 1994). A total of 13 species of Hydraena were collected, and the site is the type locality of seven species, six of which are only known from there. Probably because of the collection method, via rotenone, the specimens were not well preserved and most of them lack some or all of the legs, or parts of legs, and maxillary palpi. The species in the Pala group from Koje are quite difficult, and require dissection of males for reliable determinations. Because of this decomposed condition, many females (ca. 300) from the Koje site were not identified.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	description	(Figs. 202, 204, 411, 527)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, Gurakor Creek, ex gravel banks, [GE est.] 900 – 1100 m, 6 ° 50 ' S, 146 ° 37 ' E, 30 xii 1964, M. E. Bacchus (MEB 133) (NHM). Paratypes (14): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (10 NMW); Morobe Province: Same data as holotype (3 NHM); Western Highlands Province: Bayer / Rokina, Antenge River, [GE est.] 1100 – 1300 m, 5 ° 32 ' S, 144 ° 18 ' E, 1 v 1979, W. G. Ullrich (1 MHNG).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	diagnosis	Differential Diagnosis. Very similar in color, body form and dorsal sculpture to H. palamita (Figs. 202, 207); differing therefrom in slightly larger size (ca. 1.58 vs. 1.47 mm) and the slightly more widely separated plaques (ratios ca. 6 / 1 / 6 / 6 vs. 6 / 1 / 6 / 5). The male genitalia show a similarity in basic plan, but differ distinctively in several details, most notably the shape of the left paramere (Figs. 204, 209); reliable determinations will require examination of the aedeagi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.58 / 0.66; head 0.25 / 0.36; pronotum 0.38 / 0.49, PA 0.37, PB 0.40; elytra 0.97 / 0.66. Dorsum of head dark brown to reddish brown; pronotum light brown to testaceous; elytra dark brown to reddish brown, with very faint slightly more lightly colored macula at posterior declivity; legs brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum micropunctulate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin emarginate; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow; PF 3 moderately deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 6 / 6. P 1 ca. 1 / 2 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, length slightly less than width, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of very deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slender. Profemur (male) with very small tubercle next to trochanter; protibia slightly arcuate, distal 1 / 3 widened anteriorly, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched, each side of notch produced in point. Aedeagus as illustrated (Fig. 204). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 411).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	etymology	Etymology. " Socket of a ring for a jewel, bezel "; named in reference to the prosternal fovea.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B15FFE2FF79F43FFB9BFB36.taxon	distribution	Distribution. Currently known from three localities at three quite different elevations: central Area 1 (1100 – 1300 m), eastern Area 2 (160 m), and far eastern Area 2 (900 – 1100 m) (Fig. 527).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	description	(Figs. 203, 205, 531)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Madang, Ohu Village, 160 m, 5 ° 13.923 ' S, 145 ° 40.763 ' E, 30 iv 2006, Balke & Sagata (PNG 49) (ZSM). Paratypes (29): Madang Province: Adelbert Mts., Sewan – Keki, 700 m, 4 ° 42.215 ' S, 145 ° 25.154 ' E, 4 v 2006, Balke & Manaono (PNG 51) (3 ZSM); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (2 ZSM); Keki – Sewan, Adelbert Mts., 700 m, 4 ° 41.802 ' S, 145 ° 25.46 ' E, 30 xi 2006, Binatang Boys (PNG 120) (24 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	diagnosis	Differential Diagnosis. Similar in general dorsal coloration and pronotal shape and sculpture to H. nanopala (Figs. 203, 206); differing therefrom in larger size (ca. 1.32 vs. 1.23 mm), the presence of an ill-defined macula on the pronotum, the proportionally longer elytra (PW / EL ca. 0.58 vs. 0.63, and the slightly more widely separated plaques (ratios ca. 4 / 1 / 5 / 5 vs. 4 / 1 / 5 / 4). Among Pala group members, the mesoventral intercoxal process (P 2) is the narrowest in these two species. They also show a similarity in basic aedeagal plan, while differing distinctively in details of the distal piece (Figs. 205, 208); reliable determinations will require examination of the aedeagi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.32 / 0.58; head 0.23 / 0.32; pronotum 0.32 / 0.45, PA 0.35, PB 0.35; elytra 0.78 / 0.58. Dorsum with frons dark brown to piceous; clypeus brown; labrum testaceous; pronotum testaceous around light brown, ill-defined macula; elytra brown; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 moderately deep; PF 3 deep; PF 4 very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 5 / 5. P 1 ca. 1 / 2 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. 5 / 4, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slender. Profemur (male) with very small tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 205).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	etymology	Etymology. This species is the only member of the Pala group with a pronotal macula.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B14FFE1FF79F6D9FEEAFC82.taxon	distribution	Distribution. Currently known from three localities in the northwestern part of Area 5; elevation range 160 – 700 m (Fig. 531).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	description	(Figs. 206, 208, 528)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes: Same data as holotype (50 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	diagnosis	Differential Diagnosis. Similar in general dorsal sculpture and pronotal shape to H. maculopala (Figs. 203, 206); differing therefrom by the smaller size (ca. 1.23 vs. 1.32 mm), the lack of a pronotal macula, the broader body with proportionally shorter elytra (PW / EL ca. 0.63 vs. 0.58), and the slightly more narrowly separated plaques (ratios ca. 4 / 1 / 5 / 4 vs. 4 / 1 / 5 / 5). Among Pala group members, the mesoventral intercoxal process (P 2) is the narrowest in these two species. They also show a similarity in basic aedeagal plan, while differing distinctively in details of the distal piece (Figs. 205, 208); reliable determinations will require examination of the aedeagi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.23 / 0.58; head 0.21 / 0.32; pronotum 0.31 / 0.46, PA 0.35, PB 0.37; elytra 0.73 / 0.58. Dorsum with frons piceous, remainder of dorsum dark reddish brown, disc of pronotum slightly darker than surrounding area; legs light brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining; postmentum medially micropunctulate, otherwise finely sparsely punctulate. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 5 / 4. P 1 ca. 2.5 / 4 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely slightly concave, l / w ca. 3 / 5, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. 1.5 x P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, gradually increasing in width from base to apex, medial margin flat in distal 1 / 4. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 208).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	etymology	Etymology. Named in reference to the small size; the smallest member of the Pala group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B17FFE0FF79F14AFEEDFEF2.taxon	distribution	Distribution. Currently known only from the type locality, Kojé Creek, in the eastern arm of Area 3; elevation 160 m (Fig. 528).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	description	(Figs. 207, 209, 533)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	materials_examined	Type Material. Holotype (male): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, river, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200) (NHM). Paratypes (35): Central Province: nr. Port Moresby, Sogeri Plateau, Musgrave River, ex gravel banks, [GE est.] 100 – 200 m, 9 ° 46 ' S, 147 ° 41 ' E, 16 iii 1965, M. E. Bacchus (MEB 200 a) (31 NHM); Madang Province: Ramu Valley, 2 km SE Brahman, [GE est.] 130 – 150 m, 5 ° 43 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (1 MCZ); Sandaun Province: Mianmin, river, 990 m, 4 ° 54.57 ' S, 141 ° 35.49 ' E, 23 x 2008, S. Ibalim (PNG 192) (1 ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	diagnosis	Differential Diagnosis. Very similar in color, body form and dorsal sculpture to H. pala (Figs. 202, 207); differing therefrom in the slightly smaller size (ca. 1.47 mm vs. 1.58) and the slightly more narrowly separated plaques (ratios ca. 6 / 1 / 6 / 5 vs. 6 / 1 / 6 / 6). The male genitalia show a similarity in basic plan, but differ distinctively in several details, most notably the shape of the left paramere (Figs. 204, 209); reliable determinations will require examination of the aedeagi.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.47 / 0.60; head 0.26 / 0.32; pronotum 0.33 / 0.46, PA 0.36, PB 0.37; elytra 0.86 / 0.60. Dorsum of head dark brown to reddish brown; pronotum light brown to testaceous; elytra dark brown to reddish brown, with faint light brown macula at posterior declivity; legs brown to light reddish brown; maxillary palpi light brown to testaceous, tip not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin emarginate; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 6 / 5. P 1 ca. 2 / 3 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. equal, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, parallel, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. equal P 2. All legs long and slender. Profemur (male) without tubercle next to trochanter; protibia straight, anterior margin very slightly widened subapically. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched, each side of notch produced in point. Aedeagus as illustrated (Fig. 209).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	etymology	Etymology. " Pala's father's sister "; named in reference to the relationship to H. pala.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B16FFE0FF79F39AFB6CF8DC.taxon	distribution	Distribution. Currently known from three widely disjunct areas: Mianmin area (Area 1 or 2; 990 – 1080 m), Ramu Valley (Area 2 or 3; 130 – 150 m), and near Port Moresby (Area 11; 100 – 200 m) (Fig. 533).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	description	(Figs. 210, 212, 529)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	materials_examined	Type Material. Holotype (male): East Sepik Province: Prince Alexander Mts., Wewak, 400 m, 3 ° 37.319 ' S, 143 ° 36.764 ' E, 21 iv 2006, Balke & Sagata (PNG 45) (ZSM). Paratypes: Same data as holotype (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	diagnosis	Differential Diagnosis. Similar in pronotal shape (both with PL / PW ca. 0.72), and dorsal sculpture to H. palamita (Figs. 207, 210); differing therefrom by the much smaller size (ca. 1.29 vs. 1.47 mm), the proportionally shorter elytra (PW / EL ca. 0.57 vs. 0.53), the faint macula on the elytra, and the slightly different plaque ratios (ca. 5 / 1 / 5 / 6 vs. 6 / 1 / 6 / 5). The aedeagi of the two species distinctively differ (Figs. 209, 212).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.29 / 0.57; head 0.22 / 0.31; pronotum 0.31 / 0.43, PA 0.34, PB 0.36; elytra 0.76 / 0.57. Head with frons dark brown, clypeus and labrum brown to light brown; pronotum light brown to testaceous; elytra dark brown to reddish brown, with faint light brown macula at posterior declivity; legs light brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin emarginate; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow; PF 3 moderately deep; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 5 / 6. P 1 ca. 2 / 5 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. 3 / 5, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin slightly greater than P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate, anterior margin very slightly widened subapically, medial margin flat except small sharp tubercle subapically on posteromedial margin. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 212).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	etymology	Etymology. This member of the Pala group has a particularly pleasing body form.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE7FF79F2BAFCEFFAE1.taxon	distribution	Distribution. Currently known only from the type locality, Wewak, in the Prince Alexander Mts.; this locality is in the eastern extreme of Area 4; elevation 400 m (Fig. 529).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	description	(Figs. 211, 213, 528)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes: Same data as holotype (1 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	diagnosis	Differential Diagnosis. Differing from the other members of the Pala group by the shape of the prosternal median carina, which extends the entire length of the prosternum, is straight or very weakly arcuate in profile. Similar to H. torosopala in dorsal color and plaque ratios; differing therefrom by the smaller size (1.29 vs. 1.45 mm), the slightly broader form, and the prosternum differences (Figs. 211, 214). The male genitalia of the two species distinctively differ (Figs. 213, 216). Also see the diagnosis of H. koje.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.29 / 0.61; head 0.21 / 0.32; pronotum 0.32 / 0.50, PA 0.36, PB 0.40; elytra 0.76 / 0.61. Dorsum with frons, clypeus, and elytra dark reddish brown; pronotum and legs brown to light brown; labrum and maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 – 2 xef, larger and denser near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum very transverse, ca. median 1 / 2 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd of smallest frons punctures, interstices shining, 1 – 2 xpd, punctures not noticeably larger or denser at anterior and posterior; PF 1 absent or very shallow; PF 2 very shallow, obsolete; PF 3 shallow; PF 4 absent or very shallow. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 4 xpd, as are interstices between punctures of a row. Apices in dorsal aspect slightly separately rounded, minutely denticulate, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 7 / 1 / 5 / 5. P 1 ca. 6 / 7 P 2; median carina extending for entire length of prosternum, straight or very weakly arcuate in profile. P 2 transversely concave, l / w ca. 4 / 7, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS fused with first abdominal ventrite, width between metacoxae ca. 6 / 7 P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, gradually increasing in width from base to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 213).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	etymology	Etymology. " Three keels "; named in reference to the median longitudinal carina of the prosternum, and the two carinate plaques.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B11FFE6FF79F7E7FEEDFC32.taxon	distribution	Distribution. Currently known only from the type locality, Kojé Creek, in the eastern arm of Area 3; elevation 160 m (Fig. 528).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	description	(Figs. 214, 216, 532)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	diagnosis	Differential Diagnosis. Similar to H. tritropis in dorsal color and plaque ratios; differing therefrom by the larger size (1.45 vs. 1.29 mm), the proportionally smaller pronotum (PW / EL ca. 0.62 vs. 0.66), and the concave prosternal intercoxal process (Figs. 211, 214). The male genitalia of the two species distinctively differ (Figs. 213, 216).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.45 / 0.69; head 0.22 / 0.36; pronotum 0.36 / 0.53, PA 0.39, PB 0.43; elytra 0.86 / 0.69. Dorsum of head with frons dark brown to dark reddish brown, clypeus lighter, brown, labrum testaceous; pronotum light brown to testaceous; elytra dark brown to dark reddish brown; legs and maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 xef, very slightly, if at all, larger and denser near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 7 / 1 / 5 / 5. P 1 ca. 4 / 7 P 2; median carina anterior to coxae, straight in profile; intercoxal process wide, medially concave. P 2 transversely concave, l / w ca. 5 / 7, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. equal P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate, anterior margin slightly widened subapically. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Pronotum very transverse, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures very slightly, if at all, larger and denser at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 shallow; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Aedeagus as illustrated (Fig. 216).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	etymology	Etymology. " Muscular, bulging "; named in reference to the thick cuticle between the pro- and mesocoxae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B10FFE5FF79F1DAFDF4FED6.taxon	distribution	Distribution. Currently known only from the type locality, Keki, in the Adelbert Mts., in the northwestern part of Area 5; elevation 400 m (Fig. 532).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	description	(Figs. 215, 217, 528)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes: Same data as holotype (98 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	diagnosis	Differential Diagnosis. Similar in small size (ca. 1.29 mm) and color to H. tritropis (Figs. 211, 215); differing therefrom by the narrower body, the proportionally smaller pronotum (PW / EL ca. 0.59 vs. 0.66), the concave prosternal intercoxal process, and the narrower mesoventral intercoxal process (plaque ratios ca. 6 / 1 / 5 / 5 vs. 7 / 1 / 5 / 5). The male genitalia of the two species show some similarity in basic plan, but distinctively differ in many details (Figs. 213, 217).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.29 / 0.57; head 0.21 / 0.32; pronotum 0.30 / 0.46, PA 0.35, PB 0.37; elytra 0.78 / 0.57. Dorsum generally reddish brown, frons and elytra distinctly more darkly colored than pronotum and clypeus; legs light brown to light reddish brown; maxillary palpi testaceous, tip not darker. Frons punctures ca. 1 – 2 xef, larger near eyes than medially; interstices shining, 1 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures slightly larger and denser at anterior and posterior; PF 1 very shallow, obsolete; PF 2 very shallow; PF 3 moderately deep; PF 4 very shallow. Elytra with summit of posterior declivity slightly anterior to midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect slightly separately rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 5 / 5. P 1 ca. 2 / 3 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. 5 / 6, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. equal P 2. All legs moderately long and slender. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 217).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	etymology	Etymology. Named in reference to the type locality.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE5FF79F3B9FEEDF901.taxon	distribution	Distribution. Currently known only from the type locality, Kojé Creek, in the eastern arm of Area 3; elevation 160 m (Fig. 528).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	description	(Figs. 218, 220, 528)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Sepik Ramu Basin, Kojé Creek, unshaded creek, small to medium cobbles, gravel and fine sand (the latter in areas of slack water), filamentous algae on stony substrates, small accumulations of leaf litter, 160 m, 5 ° 33 ' S, 145 ° 23 ' E, 1 vii – 30 viii 1988, D. Dudgeon (NMW). Paratypes: Same data as holotype (6 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	diagnosis	Differential Diagnosis. A broad, banded species, somewhat similar to H. fasciolata in habitus (Figs. 218, 219); differing therefrom by the smaller size (ca. 1.38 vs. 1.44 mm), the less distinctly color-banded elytra, and the less widely spaced procoxae (plaque ratios ca. 7 / 1 / 6 / 8 vs. 9 / 1 / 6 / 8). The male genitalia of the two species differ markedly (Figs. 220, 221).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.38 / 0.66; head 0.18 / 0.34; pronotum 0.36 / 0.53, PA 0.39, PB 0.45; elytra 0.86 / 0.66. Dorsum distinctively banded: labrum and clypeus light brown to testaceous; frons dark brown; pronotum testaceous; elytra dark brown in anterior ca. 7 / 15, with testaceous fascia at posterior declivity, and similarly colored band across elytral apices, the two testaceous areas separated by light brown crescent shaped band; legs and maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 1 – 3 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum subcordiform, ca. median 3 / 4 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 3 xpd, punctures not appreciably larger at anterior and posterior; PF 1 absent; PF 2 very shallow, obsolete; PF 3 shallow; PF 4 absent. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins rather wide in anterior 1 / 2 where sides of elytra gradually sloping; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 5 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 7 / 1 / 6 / 8. P 1 ca. 5 / 7 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. 5 / 7, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, converging slightly anteriorly, at sides of very deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. equal P 2. All legs moderately long and slender. Profemur (male) with very small tubercle next to trochanter; protibia arcuate, gradually increasing in width from base to apex. Mesotibia very slightly arcuate. Metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 220).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	etymology	Etymology. Named in honor of aquatic ecologist David Dudgeon, collector of this and other new species of PNG Hydraena.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B13FFE4FF79F4C7FEEAFB52.taxon	distribution	Distribution. Currently known only from the type locality, Kojé Creek, in the eastern arm of Area 3; elevation 160 m (Fig. 528).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	description	(Figs. 219, 221, 530)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Madang, Ohu Village, 160 m, 5 ° 13.923 ' S, 145 ° 40.763 ' E, 30 iv 2006, Balke & Sagata (PNG 49) (ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	diagnosis	Differential Diagnosis. A distinctively banded, very broad species. Somewhat similar to H. dudgeoni in habitus, both having a very transverse pronotum (Figs. 218, 219), but more markedly color banded, and with more widely spaced coxae (plaque ratios ca. 9 / 1 / 6 / 8 vs. 7 / 1 / 6 / 8). This species has the widest separation of the mesocoxae. The male genitalia of the two species differ markedly (Figs. 220, 221).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.44 / 0.68; head 0.23 / 0.35; pronotum 0.36 / 0.55, PA 0.43, PB 0.46; elytra 0.84 / 0.68. Dorsum very distinctively banded: labrum and clypeus light brown to testaceous; frons dark brown; pronotum testaceous; elytra dark brown with light brown to testaceous fascia at posterior declivity, and similarly colored band across elytral apices; legs and maxillary palpi testaceous, tip of palpus not darker. Frons punctures ca. 1 xef, slightly larger near eyes than medially; interstices shining, 2 – 4 xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum very transverse, sides markedly rounded, ca. median 5 / 7 of anterior margin arcuate to posterior; punctures on disc ca. 1 xpd frons punctures, interstices shining, 1 – 2 xpd, punctures not appreciably larger or denser at anterior and posterior; PF 1 absent; PF 2 absent or so shallow as to be almost imperceptible; PF 3 shallow; PF 4 absent. Elytra with summit of posterior declivity anterior to midlength; lateral explanate margins rather wide in anterior 1 / 2 where sides of elytra gradually sloping; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 5 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 9 / 1 / 6 / 8. P 1 ca. 2 / 3 P 2; median carina straight in profile; postcoxal process medially concave. P 2 transversely concave, l / w ca. 4 / 9, sides slightly diverging toward blunt apex. Plaques very narrow, carinate, very slightly arcuate, converging slightly anteriorly, at sides of deep median depression. Metaventrite concave between P 2 and plaques. AIS width at straight posterior margin ca. equal P 2. All legs rather short, moderately slender. Profemur (male) with small tubercle next to trochanter; protibia arcuate. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus as illustrated (Fig. 221).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	etymology	Etymology. Named in reference to the dorsal fasciae, and wide body.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B12FFEBFF79F73AFE7CFD31.taxon	distribution	Distribution. Currently known only from the type locality, Ohu Village, in the northwestern part of Area 5; elevation 160 m (Fig. 530).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEBFF79F0D1FCC5FA0D.taxon	description	Males of one species, H. apexa, have distinctively arcuate metatibiae. The male genitalia in this group have a diagnositic combination of characters: the distal piece has a very large process on the right side, the parameres are long and narrow, and the dorsal surface has a cluster of setae on each side, at the juncture of the main piece and distal piece (Figs. 224, 225, 228). The female tergite X, gonocoxite, and spermatheca of H. ulna and H. pectenata are illustrated (Figs. 412, 413); these differ slightly in proportions, but both have tergite X with three incisions, delimiting four lobes. Members of the Ulna group have been collected at an elevation range of 1067 – 1670 m (maps Figs. 535 – 537). As is currently known, Areas 1, 5, and 6 each have an endemic species. Available microhabitat data mostly indicate pool biotopes: under wet leaves left by receding pond; small pool, probably permanent, in clay in dense shade; gravel banks of swift shallow clear river; shallow pools in marsh.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEAFF79F7CBFE9DFB99.taxon	description	(Figs. 222, 224, 412, 537)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEAFF79F7CBFE9DFB99.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex shallow pools in marsh, 1128 m, 6 ° 48 ' S, 146 ° 48 ' E, 8 i 1965, M. E. Bacchus (MEB 144) (NHM). Paratypes (13): Morobe Province: Same data as holotype (3 NHM); Herzog Mts., Vagau [Wagau], ex gravel banks of swift shallow clear river, 1128 m, 6 ° 48 ' S, 146 ° 48 ' E, 8 i 1965, M. E. Bacchus (MEB 145 a) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEAFF79F7CBFE9DFB99.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus and plaque ratios to H. pectenata (Figs. 222, 223); differing therefrom in slightly larger size (ca. 1.57 vs. 1.46 mm), less densely punctate pronotum (discal interstices ca. 2 – 4 vs. 1 – 2 xpd). The male genitalia of the two species also show a relationship, while differing distinctively in several details (Figs. 224, 225).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEAFF79F7CBFE9DFB99.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.57 / 0.69; head 0.21 / 0.36; pronotum 0.40 / 0.53, PA 0.41, PB 0.48; elytra 0.97 / 0.69. Dorsum of head dark brown to piceous; pronotum dark brown around piceous, very diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 8 / 15 / 5; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 2 xef near eyes, smaller and sparser medially; interstices shining, 1 – 4 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum effacedly microreticulate, very sparsely very finely punctulate, weakly shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, anterior margin straight, sides straight between anterior angle and widest part, arcuate at middle, sinuate between widest part and slightly outward turning posterior angle; punctures on disc ca. 2 xpd largest frons punctures, interstices shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly ca. 2 xpd those on disc; PF 1, PF 2 and PF 4 very shallow; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 8 / 4. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 3, sides very slightly converging toward blunt, slightly raised apex. Plaques flat, at sloping sides of median depression, anteriorly tapering and convergent, narrowly separated at anterior extreme. Metaventrite between mesocoxae very weakly raised in midline. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia straight, medial margin slightly emarginate over middle 1 / 3, then widened in distal 1 / 3, greatest width ca. twice width at midlength. Meso- and metatibia straight, slender. Abdominal apex very slightly asymmetrical; last tergite (male) with very small apicomedian notch. Aedeagus as illustrated (Fig. 224). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 412).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1DFFEAFF79F7CBFE9DFB99.taxon	etymology	Etymology. Named in reference to the elbow-shaped process of the aedeagus. Distribution. Currently known only from the type locality, Wagau, in the Herzog Mts. (Area 6), elevation 1128 m (Fig. 537).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	description	(Figs. 223, 225, 413, 536)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex small pool, probably permanent, in clay in dense shade, 1067 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 39) (NHM). Paratypes: Same data as holotype (213 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus and plaque ratios to H. ulna (Figs. 222, 223); differing therefrom in slightly smaller size (ca. 1.46 vs. 1. 57 mm), more densely punctate pronotum (discal interstices ca. 1 – 2 vs. 2 – 4 xpd). The male genitalia of the two species also show a relationship, while differing distinctively in several details (Figs. 224, 225).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.46 / 0.65; head 0.20 / 0.34; pronotum 0.40 / 0.50, PA 0.38, PB 0.46; elytra 0.87 / 0.65. Dorsum of head dark brown to piceous; pronotum dark brown in front of and behind piceous, very diffusely margined, fascia, ratios of color bands, as measured in midline, ca. 7 / 15 / 5; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices 1 – 4 xpd, microreticulate and dull laterally, smooth and shining medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum effacedly microreticulate, very sparsely very finely punctulate, weakly shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, anterior margin straight, sides straight or very slightly arcuate between anterior angle and widest part, arcuate at middle, sinuate between widest part and posterior angle; punctures on disc ca. 2 – 3 xpd largest frons punctures, interstices shining, ca. 1 – 2 xpd, punctures anteriorly and posteriorly ca. 2 xpd those on disc; PF 1, PF 2 and PF 4 very shallow; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 8 / 3. P 1 laminate; median carina sinuate in profile, slightly raised behind coxae. P 2 length / width ca. 5 / 3, sides very slightly diverging toward blunt, slightly raised apex. Plaques flat or slightly rounded, at sloping sides of median depression, anteriorly tapering and convergent, narrowly separated at anterior extreme. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length. Profemur (male) with small tubercle on ventral margin near trochanter; protibia straight, medial margin slightly widened in distal 1 / 2. Meso- and metatibia straight, slender. Abdominal apex very slightly asymmetrical; last tergite (male) with very small apicomedian notch. Aedeagus as illustrated (Fig. 225). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 413).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	etymology	Etymology. " Comb-like qualities "; named in reference to the rows of spines on the meso- and metatibiae of males, the slender processes of the aedeagus, and the dentate tenth tergum of females.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1CFFE9FF79F673FD23FD3E.taxon	distribution	Distribution. Currently known only from the type locality, Damanti, in the Finisterre Mts. (Area 5), at the bor- der with Area 3; elevation 1067 m (Fig. 536).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	description	(Figs. 226, 228, 535)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Okapa, under wet leaves left by receding pond, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 190) (NHM). Paratypes: Eastern Highlands Province: Aiyura, 1670 m, 6 ° 21.131 ' S, 145 ° 54.398 ' E, 5 iv 2006, Balke & Sagata (PNG 32) (57 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	diagnosis	Differential Diagnosis. Recognized among members of the Ulna group (Figs. 222, 223, 226) by the comparatively large size (ca. 1.85 vs. 1.46 and 1.57 mm), the rather wide pronotum that is emarginate between the anterior angle and widest point, and the comparatively large metaventral plaques (plaque ratios ca. 4 / 3 / 10 / 5). Males additionally recognized by the arcuate metatibiae, and the markedly asymmetrical abdominal apex. The male genitalia distinctively differ from those of the other two species in the Ulna group (Fig. 228).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.85 / 0.81; head 0.26 / 0.41; pronotum 0.46 / 0.64, PA 0.47, PB 0.53; elytra 1.13 / 0.81. Dorsum of head dark brown to piceous; pronotum dark brown around piceous, very diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 8 / 18 / 5; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices 1 – 4 xpd, laterally microreticulate, dull, medially shining. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum effacedly microreticulate, very sparsely very finely punctulate, weakly shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, anterior margin straight, sides slightly emarginate between anterior angle and widest part, arcuate at middle, sinuate between widest part and posterior angle; punctures on disc ca. 2 – 3 xpd largest frons punctures, interstices shining, ca. 1 – 3 xpd, punctures anteriorly and posteriorly ca. 3 – 4 xpd those on disc; PF 1 and PF 2 very shallow; PF 3 moderately deep, wide; PF 4 absent. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins rather wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect separately rounded, in posterior aspect margins forming rather deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 3 / 10 / 5. P 1 laminate; median carina sinuate in profile, slightly raised behind coxae. P 2 length / width ca. 7 / 4, sides parallel, apex blunt, slightly raised. Plaques large, flat or slightly raised, widest at midlength, at sloping sides of median depression, anteriorly tapering and convergent, narrowly separated at anterior extreme. Metaventrite between mesocoxae very weakly raised in midline. AIS width at straight posterior margin slightly less than 2 x P 2. All legs of moderate length. Profemur (male) with minute tubercle on ventral margin near trochanter; protibia very slightly arcuate, medial margin slightly emarginate and concave, except distal 1 / 4 widened, posteromedial margin of concavity with row of short spines. Mesotibia straight, slender. Metatibia slender, slightly arcuate, distal 1 / 2 of medial margin with brush of setae. Abdominal apex markedly asymmetrical; last tergite (male) with large notch, offset to right side. Aedeagus as illustrated (Fig. 228).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	etymology	Etymology. Named in reference to the pointed processes of the aedeagus, and to the relatively long apical area of the pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1FFFE8FF79F0D1FF64FE3A.taxon	distribution	Distribution. Currently known from two localities in eastern Area 1; elevations 1524 m and 1670 m (Fig. 535).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	description	(Figs. 227, 229, 352 – 357, 358 – 361, 414, 557)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Markham Valley, Lae – Kainantu road, Erap River, ex gravel, [GE est.] 80 – 130 m, 6 ° 37 ' S, 146 ° 42 ' E, 26 i 1965, M. E. Bacchus (MEB 156) (NHM). Paratypes (43): Central Province: Loloki, 10 miles N of Port Moresby, ex gravel in roadside drain, [GE est.] 30 – 50 m, 9 ° 20 ' S, 147 ° 10 ' E, 19 iii 1965, M. E. Bacchus (MEB 209) (2 NHM); Loloki, 10 miles N of Port Moresby, ex swamp, much grass, [GE est.] 30 – 50 m, 9 ° 20 ' S, 147 ° 10 ' E, 19 iii 1965, M. E. Bacchus (MEB 208) (6 NHM); Moitaka, 7 miles N of Port Moresby, ex dead leaves in gravelly shallow of small pond, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 207) (24 NHM); Moitaka, 7 miles N of Port Moresby, very muddy gravel bank of field drain, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 204) (1 NHM); Port Moresby – Brown River road, ex grassy shallows of large muddy pond, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 195) (5 NHM); Morobe Province: c. 7 miles Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (1 NHM); Markham Valley, Gusap, 90 miles NW of Lae, ex dead leaves on mud wetted by seepage, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 163) (4 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	diagnosis	Differential Diagnosis. Similar to H. ramuquintana in dorsal habitus, small size (ca. 1.23 mm), and subserial to random discal elytral punctures (Figs. 227, 230); differing therefrom ventrally in plaque ratios, H. quintana having the plaques more convergent anteriorly and P 2 narrower (ratios ca. 2 / 2 / 7 / 3 vs. 3 / 1.5 / 5 / 4). Males of the two species are immediately differentiated by the highly modified abdominal ventrites of H. quintana (SEM Figs. 356, 357, 361). The ventrites are similarly modified in H. buquintana, but that species is larger (ca. 1.33 mm), and more strongly punctate dorsally. The male genitalia of all three species in the Quintana group distinctively differ from one another in the shapes of the processes of the distal piece (Figs. 229, 232, 233). The prosternum, meso- and metaventrite, antennal pocket, abdominal apex, and chaetotaxy of the protibiae are illustrated with SEMs (Figs. 352 – 357, 358 – 361).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.23 / 0.52; head 0.21 / 0.28; pronotum 0.31 / 0.38, PA 0.31, PB 0.36; elytra 0.71 / 0.52. Dorsum of head dark brown to piceous; pronotum brown to light brown in front of and behind dark brown, diffusely margined, fascia, ratios of color bands, as measured in midline, ca. 6 / 10 / 4; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum, especially pronotum, strongly shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices shining, 1 – 5 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc very fine and very sparse, slightly smaller than largest frons punctures, interstices strongly shining, ca. 6 – 8 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, obsolete; PF 3 moderately deep, wide. Elytra widest at about anterior 1 / 3; summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures subserial or random, ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, weakly shining, on disc ca. 1 – 2 xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming moderately deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 2 / 7 / 3. P 1 laminate; median carina sinuate in profile, raised behind coxae. P 2 length / width ca. 5 / 2, sides very slightly diverging toward blunt, raised apex. Plaques large, flat or slightly rounded, at sloping sides of median depression, anteriorly tapering and convergent, narrowly separated at anterior extreme. Metaventrite between mesocoxae raised to joint tip of P 2. AIS width at straight posterior margin ca. 2 x P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia straight, medial margin slightly widened in distal 1 / 2 and with row of short spines. Meso- and metatibia straight, slender. Abdominal apex marked modified in males. Aedeagus as illustrated (Fig. 229). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 414).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	etymology	Etymology. Named in reference to the modified male fifth abdominal sternum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1EFFEFFF79F773FD73FAEE.taxon	distribution	Distribution. Currently known from two disjunct lowland areas: the eastern arm of Area 3 (10 – 305 m), and the central part of Area 11 (30 – 100 m) (Fig. 557).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	description	(Figs. 230, 232, 558)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, 6 km N Brahman, [GE est.] 130 – 150 m, 5 ° 38 ' S, 145 ° 22 ' E, 21 vi 1991, D. Larson (MCZ). Paratypes: Same data as holotype (2 MCZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	diagnosis	Differential Diagnosis. Similar to H. quintana in dorsal habitus, small size (ca. 1.21 mm), and subserial to random discal elytral punctures (Figs. 227, 230); differing therefrom ventrally in plaque ratios, H. ramuquintana having the plaques less convergent anteriorly and P 2 wider (ratios ca. 3 / 1.5 / 5 / 4 vs. 2 / 2 / 73). Males of the two species are immediately differentiated by the highly modified abdominal ventrites of H. quintana (SEM Figs. 356, 357, 361). The male genitalia of all three species in the Quintana group distinctively differ from one another in the shapes of the processes of the distal piece (Figs. 229, 232, 233).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.21 / 0.50; head 0.22 / 0.30; pronotum 0.33 / 0.41, PA 0.32, PB 0.37; elytra 0.71 / 0.50. Dorsum of head dark brown to piceous, lateral areas of clypeus slightly lighter; pronotum testaceous in front of and behind brown to dark brown, diffusely margined, fascia, ratios of color bands, as measured in midline, ca. 5 / 11 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices shining, 1 – 5 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum effacedly microreticulate, very sparsely very finely punctulate, weakly shining. Postmentum microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc very fine and very sparse, slightly smaller than largest frons punctures, interstices shining, ca. 6 – 8 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped impression; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins narrow; on basal 1 / 3 punctures subserial to random, ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming moderately deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 1.5 / 5 / 4. P 1 laminate; median carina sinuate in profile, slightly raised behind coxae. P 2 length / width ca. 5 / 3, sides very slightly diverging toward blunt, raised apex. Plaques slightly rounded, at sides of median depression, anteriorly tapering and slightly convergent. Metaventrite between mesocoxae very weakly raised in midline. AIS width at straight posterior margin slightly wider than P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia straight, very slightly widened on medial margin at about midlength. Meso- and metatibia straight, slender. Abdominal apex very slightly asymmetrical; last tergite (male) with very small apicomedian notch. Aedeagus as illustrated (Fig. 232).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	etymology	Etymology. Named in reference to the geographical distribution and relationship to H. quintana.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B19FFEEFF79F7EBFCB5FC5E.taxon	distribution	Distribution. Currently known only from the type locality near Brahman in the Ramu Valley; this is in the eastern arm of Area 3; elevation 130 – 150 m (Fig. 558).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	description	(Figs. 231, 233, 513)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	materials_examined	Type Material. Holotype (male): Western Highlands Province: Mt. Hagen town area, 1600 m, 5 ° 51.491 ' S, 144 ° 20.194 ' E, 7 xii 2006, Balke & Kinibel (PNG 130) (ZSM). Paratypes: Same data as holotype (1 male ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Quintana group by the larger size (ca. 1.33 vs. 1.23 mm), the denser pronotal punctation, the more regularly serial discal elytral punctures, the more strongly microreticulate frons, the narrower testaceous borders around the pronotal fascia, and the slightly longer dorsal setae (Fig. 231). Males have the abdominal ventrites modified similar to those of H. quintana (SEM Figs. 356, 357). The male genitalia of all three species in the Quintana group distinctively differ from one another in the shapes of the processes of the distal piece (Figs. 229, 232, 233).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.56; head 0.19 / 0.31; pronotum 0.33 / 0.45, PA 0.35, PB 0.42; elytra 0.82 / 0.56. Dorsum of head dark brown to piceous, lateral areas of clypeus slightly lighter; pronotum light brown in front of and behind dark brown to piceous, diffusely margined fascia, ratios of color bands, as measured in midline, ca. 5 / 12 / 5; elytra dark brown; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices 1 – 5 xpd, microreticulate and dull laterally, shining medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum microreticulate, finely punctulate, dull. Postmentum concave, microreticulate, dull. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc very fine and very sparse, slightly smaller than largest frons punctures, interstices shining, ca. 4 – 6 xpd, punctures anteriorly and posteriorly slightly larger and denser than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, obsolete; PF 3 moderately deep, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 some punctures subserial, ca. 1 xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 3 / 2 / 7 / 4. P 1 laminate; median carina sinuate in profile, slightly raised between coxae. P 2 length / width ca. 5 / 3, sides very slightly diverging toward blunt, slightly raised apex. Plaques flat, lateral margins arcuate, at sloping sides of median depression, anteriorly tapering and slightly convergent. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. equal P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia very slightly arcuate, medial margin slightly widened in distal 1 / 2 and with row of short spines. Meso- and metatibia straight, slender. Abdominal apex markedly modified in males, similar to that of H. quintana (SEM Figs. 356, 357, 361); 5 th ventrite with oblique tubercle on each side of midline; 6 th ventrite weakly concave. Aedeagus as illustrated (Fig. 233).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	etymology	Etymology. Named in reference to the size and relationship to H. quintana.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B18FFEDFF79F63BFE01FD81.taxon	distribution	Distribution. Currently known only from the type locality, Mt. Hagen town area, in south central Area 1; elevation 1600 m (Fig. 513).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	description	(Figs. 234, 236, 373 – 375, 415, 539)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], small pools in clay rainwater gulley, 1524 m, 6 ° 48 ' S, 146 ° 48 ' E, 12 i 1965, M. E. Bacchus (MEB 150) (NHM). Paratypes (19): Eastern Highlands Province: Marawaka, Ande, 1700 – 1800 m, 7 ° 1.697 ' S, 145 ° 49.807 ' E, 9 xi 2006, Balke & Kinibel (PNG 87) (5 ZSM); Okapa, large muddy pond, no vegetation, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 185) (4 NHM); Morobe Province: ca. 10 km S Garaina Saureri, 1600 m, 7 ° 55 ' S, 147 ° 5 ' E, 24 iii 1998, A. Riedel (1 NMW); Herzog Mts., Vagau [Wagau], small pools in clay rain-water gulley, 1524 m, 6 ° 48 ' S, 146 ° 48 ' E, 12 i 1965, M. E. Bacchus (MEB 150) (9 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Incisiva group by the unicolored reddish brown dorsum (other species have a pronotal macula) (Fig. 234). The metaventral plaques are slightly shorter (compared with their separation) than those of the other Incisiva group members (ratios ca. 5 / 2 / 6 / 5). The male hind tibiae are widest at midlength, similar to H. carinocisiva. The aedeagus is very distinctive and should be examined for reliable determinations (Fig. 236). The prosternum, meso- and metaventrite, abdominal apex of female, and very complicated chaetotaxy of the tibiae are illustrated with SEMs (Figs. 373 – 375).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.58 / 0.66; head 0.21 / 0.34; pronotum 0.39 / 0.53, PA 0.39, PB 0.50; elytra 0.96 / 0.66. Dorsum and legs reddish brown, frons slightly darker; maxillary palpi light reddish brown to testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 – 2 xef near eyes, smaller and much sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 2 – 4 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum microreticulate, moderately dull. Genae very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides slightly arcuate; punctures on disc ca. 1 xpd of largest frons punctures, interstices strongly shining, ca. 1 – 3 xpd; PF 1, PF 2 and PF 4 absent; PF 3 shallow. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 2 / 6 / 5. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 transversely concave, length ca. equal width, sides very slightly diverging toward blunt apex. Plaques roundly slightly raised, very slightly converging anteriorly, almost parallel, at sides of median depression. Metaventrite between mesocoxae slightly raised. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length, tibiae very slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin increasing in width from base to distal 1 / 4, then excavate to apex, few large spines at base of excavation, and contiguous row of very short spines along excavation. Mesotibia straight. Metatibia straight, narrow, but widest at midlength. Abdominal apex symmetrical, distinctly microreticulate; last tergite (male) with small apicomedian notch. Aedeagus as illustrated (Fig. 236). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 415).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	etymology	Etymology. Named in reference to the relatively simple aedeagal contours and the slender blade-like process.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1BFFECFF79F774FB70FC7A.taxon	distribution	Distribution. Currently known from four localities, two in far eastern Area 1 (1524 m, and 1700 – 1800 m), and one each in Area 6 (Herzog Mts., 1524 m), and the northern part of Area 7 (1600 m) (Fig. 539).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	description	(Figs. 235, 237, 540)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Goroka, Daulo Pass, 2500 m, 6 ° 2.432 ' S, 145 ° 13.333 ' E, 19 v 2006, John & Balke (PNG 67) (ZSM). Paratypes (12): Eastern Highlands Province: Akameku – Brahmin, Bismarck Range, 2200 m, 5 ° 56.801 ' S, 145 ° 22.238 ' E, 23 xi 2006, Balke & Kinibel (PNG 106) (1 ZSM); Akameku – Brahmin, Bismarck Range, 1900 m, 5 ° 54.284 ' S, 144 ° 22.271 ' E, 23 xi 2006, Balke & Kinibel (PNG 108) (5 ZSM); Goroka, Daulo Pass, 2500 m, 6 ° 2.432 ' S, 145 ° 13.333 ' E, 19 v 2006, John & Balke (PNG 67) (6 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	diagnosis	Differential Diagnosis. Differing from the other maculate members of the Incisiva group by the larger size (ca. 1.84 vs. 1.58 – 1.66 mm); otherwise very similar (Fig. 235). The aedeagus is very distinctive and should be examined for reliable determinations (Fig. 237).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.84 / 0.78; head 0.26 / 0.42; pronotum 0.45 / 0.61, PA 0.45, PB 0.58; elytra 1.14 / 0.78. Dorsum of head with frons dark reddish brown, clypeus brown, labrum testaceous; pronotum testaceous around light brown rectangular macula, ratios of color bands, as measured in midline, ca. 9 / 15 / 7; elytra dark brown; legs light brown; maxillary palpi light brown to testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 – 2 xef near eyes, smaller and sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 1 – 3 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate, and finely punctulate, weakly shining. Genae very slightly raised except with shallow impression in midline, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc smaller than largest frons punctures, interstices strongly shining, ca. 2 – 6 xpd, punctures posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 moderately deep. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 2 / 8 / 6. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 transversely concave, length slightly greater than width, sides parallel, apex blunt. Plaques roundly slightly raised, tapering anteriorly, very slightly converging anteriorly, almost parallel, at sides of median depression. Metaventrite flat between mesocoxae. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length, tibiae slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin increasing in width from base to distal 1 / 4, then excavate to apex, few large spines at base of excavation, and contiguous row of very short spines along excavation. Meso- and Metatibia straight, very slen- der. Abdominal apex symmetrical; last tergite (male) with small apicomedian notch. Aedeagus as illustrated (Fig. 237).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	etymology	Etymology. " Little woodpecker "; named in reference to the shape of the aedeagus.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55B1AFF13FF79F617FDA9FD3E.taxon	distribution	Distribution. Currently known from three localities in eastern Area 1, at the relatively high elevations of 1900 m, 2200 m, and 2500 m (Fig. 540).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	description	(Figs. 238, 240, 542)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Vagau [Wagau], ex dead leaves in small stream in dense forest, 1220 m, 6 ° 48 ' S, 146 ° 48 ' E, 6 i 1965, M. E. Bacchus (MEB 139) (NHM). Paratypes (4): Morobe Province: Same data as holotype (1 NHM); NE, McAdam Park, [GE est.] 700 – 900 m, 7 ° 16 ' S, 146 ° 40 ' E, 29 viii 1968, J. Balogh (No. NG – W – B. 38) (3 ISNB).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	diagnosis	Differential Diagnosis. Differing from the other maculate members of the Incisiva group by the carmel-like dorsal color and small size (ca. 1.61 mm); otherwise very similar (Fig. 238). The aedeagus is very distinctive and should be examined for reliable determinations (Fig. 240).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.61 / 0.66; head 0.23 / 0.36; pronotum 0.41 / 0.55, PA 0.41, PB 0.51; elytra 0.97 / 0.66. Dorsum of head with frons dark reddish brown, clypeus brown, labrum testaceous; pronotum testaceous around light brown rectangular macula, ratios of color bands, as measured in midline, ca. 6 / 14 / 7; elytra dark brown; legs light brown; maxillary palpi light brown to testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 – 2 xef near eyes, smaller and much sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 2 – 6 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate, weakly shining. Genae very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly smaller than largest frons punctures, interstices strongly shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 2 / 7 / 5. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length slightly greater than width, sides very slightly converging toward blunt apex. Plaques roundly slightly raised, very slightly converging anteriorly, at sides of median depression. Metaventrite between mesocoxae flat. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length. Profemur (male) without tubercle next to trochanter; protibia slightly arcuate, medial margin increasing in width from base to distal 1 / 4, then excavate to apex, few large spines at base of excavation, and contiguous row of very short spines along excavation. Mesotibia straight. Metatibia straight, very weakly emarginate on medial margin in distal 1 / 2. Abdominal apex symmetrical; last tergite (male) with small apicomedian notch. Aedeagus as illustrated (Fig. 240).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	etymology	Etymology. Carmen (sing, charm) plus mellita (honey sweet); named in reference to the rich caramel-like dorsal coloration.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE5FF12FF79F0DBFE57FE8A.taxon	distribution	Distribution. Currently known from two localities in Area 6: Herzog Mts. (1220 m) and McAdam National Park (700 – 900 m) (Fig. 542).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	description	(Figs. 239, 241, 541)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Aiyura, creek, 1670 m, 6 ° 21.131 ' S, 145 ° 54.398 ' E, 20 v 2006, John & Balke (PNG 70) (ZSM). Paratypes: Same data as holotype (4 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	diagnosis	Differential Diagnosis. Differing from the other members of the Incisiva group by the carinate metaventral plaques (plaque ratios ca. 5 / 1.5 / 7 / 5); otherwise very similar (Figs. 234, 235, 238, 239). The aedeagus is very distinctive and should be examined for reliable determinations (Fig. 241).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.66 / 0.68; head 0.25 / 0.36; pronotum 0.41 / 0.53, PA 0.40, PB 0.52; elytra 1.01 / 0.68. Dorsum of head with frons dark reddish brown, clypeus brown, labrum testaceous; pronotum testaceous around very faint, diffusely margined, light brown rectangular macula, color bands grading into one another on slightly teneral holotype, color band ratios ca. 8 / 10 / 7 on less teneral paratype; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 2 – 5 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly smaller than largest frons punctures, interstices strongly shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 moderately deep. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 4 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1.5 / 7 / 5. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 transversely concave, length ca. equal width, sides parallel or very slightly converging toward blunt apex. Plaques flat anteriorly, becoming gradually weakly raised to form low carina posteriorly, very slightly converging anteriorly, almost parallel, at sides of median depression. Metaventrite flat between mesocoxae. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) with very small tubercle next to trochanter; protibia straight, medial margin increasing in width from base to distal 1 / 4, then excavate to apex, few large spines at base of excavation, and contiguous row of very short spines along excavation. Mesotibia straight, slender. Metatibia straight, slender, widest at midlength. Abdominal apex symmetrical, distinctly microreticulate; last tergite (male) with small apicomedian notch. Aedeagus as illustrated (Fig. 241).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	etymology	Etymology. This is the only species in the Incisiva group with carinate plaques.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE4FF12FF79F342FD23F92C.taxon	distribution	Distribution. Currently known only from the type locality, Aiyura, in the far eastern part of Area 1, at the bor- der with Area 2; elevation 1670 m (Fig. 541).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	description	(Figs. 242, 244, 416, 545)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Markham Valley, Gusap, c. 90 mi. W of Lae, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 166) (NHM). Paratypes (24): Madang Province: Ramu Valley, 4.5 km N Brahman, [GE est.] 130 – 150 m, 5 ° 39 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (6 MCZ); Ramu Valley, 6 km N Brahman, [GE est.] 130 – 150 m, 5 ° 38 ' S, 145 ° 22 ' E, 21 vi 1991, D. Larson (4 MCZ); Morobe Province: Same data as holotype (4 NHM); Markham Valley, Gusap, c. 90 miles NW of Lae, large pond, muddy bottom with thick layer of dead leaves, dense Ceratophyllum, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 162) (10 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	diagnosis	Differential Diagnosis. Among members of the Fundextra group, similar to H. tholasoris in comparatively large size (ca. 1.54 and 1.50 respectively) and in dorsal sculpture (Figs. 242, 250). Hydraena fundextra has a pronotal macula whereas H. tholasoris has a fascia. The plaque ratios differ in the two species, with H. fundextra having longer and more widely separated plaques compared with P 2 (ratios ca. 4 / 1 / 8 / 7 vs. 5 / 1 / 7 / 6); in addition, the plaques are parallel in H. fundextra and anteriorly convergent in H. tholasoris. The male genitalia of H. fundextra distinctively differ from those of other members of the group (Fig. 244).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.54 / 0.72; head 0.24 / 0.37; pronotum 0.38 / 0.55, PA 0.43, PB 0.51; elytra 0.96 / 0.72. Dorsum of head with posterior 1 / 2 of frons dark brown, remainder of frons, clypeus, and labrum light brown to testaceous; pronotum testaceous around light brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 8 / 12 / 6; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 xef, not notably smaller or sparser medially; interstices weakly shining, 0.5 – 2 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 5 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly larger than largest frons punctures, interstices strongly shining, ca. 2 – 3 xpd, punctures posteriorly slightly larger and denser than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely confluent in midline to form U-shaped impression; PF 3 deep, wide. Elytra with posterior declivity very gradual, summit slightly posterior to midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 8 / 7. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 3 / 2, sides very slightly diverging toward blunt apex. Plaques carinate lines, parallel, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin ca 1.5 x P 2. All legs of moderate length. Profemur (male) with small tubercle on ventral margin near basal 1 / 3; protibia slightly arcuate, posteromedial margin widened to form narrow ridge at about midlength. Meso- and metatibia, straight, slender. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 244). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 416).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	etymology	Etymology. Named in reference to the greatly modified right paramere and to the relationship to H. funda.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE7FF10FF79F113FE22FD81.taxon	distribution	Distribution. Currently known only from the eastern arm of Area 3; four localities, with an elevation range of 130 – 305 m (Fig. 545).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	description	(Figs. 243, 245, 382 – 386, 543)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: c. 7 mi. Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (NHM). Paratypes (52): Madang Province: 5 km N Kawe, plantation drain, [GE est.] 10 – 60 m, 4 ° 58 ' S, 145 ° 47 ' E, 11 iii 1991, D. Larson (2 MCZ); Gogal Valley, 4 km S Baru Village, [GE est.] 300 – 500 m, 5 ° 42 ' S, 146 ° 32 ' E, 10 iv 1991, D. Larson (2 MCZ); Ramu Valley, 2 km SE Brahman, [GE est.] 130 – 150 m, 5 ° 43 ' S, 145 ° 22 ' E, 18 iv 1991, D. Larson (1 MCZ); Ramu Valley, 4 – 5 km SW Yagumbu, [GE est.] 400 – 600 m, 5 ° 38 ' S, 145 ° 31 ' E, 15 iv 1991, D. Larson (3 MCZ); Ramu Valley, 6 km SW Yagumbu, [GE est.] 500 – 700 m, 5 ° 39 ' S, 145 ° 32 ' E, 15 iv 1991, D. Larson (3 MCZ); Morobe Province: Same data as holotype (6 NHM); c. 7 miles Lae – Bulolo road, ex gravel and grass roots on bank of small stream, [GE est.] 10 – 30 m, 6 ° 41 ' S, 146 ° 54 ' E, 30 xii 1964, M. E. Bacchus (MEB 120) (18 NHM); Huon Pen., road to Kwapsanek, 250 m, 6 ° 30.27 ' S, 146 ° 59.581 ' E, 31 iii 2006, Balke & Sagata (PNG 24) (7 MCZ, NHM, NMW, PNG, ZSM); Lae, ex muddy gravel bank of small stream in Botanic Garden, [GE est.] 20 – 30 m, 6 ° 43 ' S, 147 ° 0 ' E, 12 xii 1964, M. E. Bacchus (MEB 118) (2 NHM); Markham Valley, Gusap, 90 miles NW of Lae, ex dead leaves on mud wetted by seepage, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 163) (5 NHM); Markham Valley, Gusap, c. 90 miles NW of Lae, large pond, muddy bottom with thick layer of dead leaves, dense Ceratophyllum, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 162) (3 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	diagnosis	Differential Diagnosis. Among members of the Fundextra group similar to H. thola in the plaque ratios, having P 2 slightly wider than the plaque separation (ratios ca. 5 / 1 / 6 / 4 and 5 / 1 / 8 / 4 respectively) (Figs. 243, 247). Hydraena bifunda differs from H. thola and all other members of the Fundextra group in the degree to which the posterior part of P 1 is raised. Hydraena bifunda differs dorsally from H. thola in the following characters: the frons is only weakly microreticulate, the pronotal punctures are only slightly larger than the frons punctures, the elytra have a few subserial discal punctures, and the pronotum has a fascia. The male genitalia of H. bifunda distinctively differ from those of other members of the group (Fig. 245). The metaventrite and complicated leg chaetotaxy are illustrated with SEMs (Figs. 382 – 386).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.60; head 0.22 / 0.33; pronotum 0.33 / 0.47, PA 0.37, PB 0.44; elytra 0.81 / 0.60. Dorsum of head dark brown; pronotum light brown to testaceous around brown, diffusely margined, fascia, ratios of color bands, as measured in midline, ca. 6 / 10 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 xef, slightly smaller and sparser medially; interstices effacedly microreticulate, weakly shining, 0.5 – 2 xpd. Clypeus effacedly microreticulate, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctulate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd of largest frons punctures, interstices strongly shining, ca. 2 – 3 xpd, punctures posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped impression; PF 3 moderately deep, wide. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 6 / 4. P 1 very slightly wider than laminate; in profile, median carina straight in front of coxae, behind coxae carina raised, arcuate in profile. P 2 markedly concave, length / width ca. 6 / 5, sides parallel or very slightly converging toward blunt apex. Plaques carinate lines, converging slightly anteriorly, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin ca. equal P 2. All legs of moderate length. Profemur (male) with minute tubercle on ventral margin near basal 1 / 3; protibia very slightly arcuate, gradually increasing in width from base to apex, ventral margin with minute carina near midlength. Meso- and metatibia straight, slender. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 245).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	etymology	Etymology. Named in reference to the paired processes of the aedeagus, and to the relationship to H. funda.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE6FF17FF79F04BFB25FC82.taxon	distribution	Distribution. Currently known from the eastern parts of Areas 2 and 3, and both eastern and western parts of Area 5; elevation range 10 – 700 m (Fig. 543). Note. The holotype is slightly teneral; mature specimens have a darker pronotal fascia.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	description	(Figs. 246, 248, 376 – 379, 544)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, ex dead leaves on mud bank, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 123) (NHM). Paratypes (56): East Sepik Province: Sepik, main river, [GE est.] 5 – 20 m, 4 ° 12 ' S, 143 ° 36 ' E, 2 iii 1965, R. W. Hornabrook (7 NMNZ); Yentchan, main Sepik River, in small stream behind village, [GE est.] 20 – 50 m, 4 ° 8 ' S, 142 ° 55 ' E, 18 iii 1965, R. W. Hornabrook (1 NMNZ); Madang Province: 5 km N Kawe, plantation drain, [GE est.] 10 – 60 m, 4 ° 58 ' S, 145 ° 47 ' E, 11 iii 1991, D. Larson (4 MCZ); 5 km NW CRI, Nagada Harb, [GE est.] 10 – 30 m, 5 ° 20 ' S, 145 ° 42 ' E, 18 iii 1991, D. Larson (1 MCZ); 7 km W Bagildik, Murnass River, [GE est.] 400 – 600 m, 4 ° 57 ' S, 145 ° 43 ' E, 8 iii 1991, D. Larson (5 MCZ); Gogal Valley, 4 km S Baru Village, [GE est.] 300 – 500 m, 5 ° 42 ' S, 146 ° 32 ' E, 10 iv 1991, D. Larson (2 MCZ); Gogal Valley, Baru Village, [GE est.] 300 – 500 m, 5 ° 40 ' S, 146 ° 32 ' E, 10 iv 1991, D. Larson (7 MCZ); Gogal Valley nr. Kokun River, [GE est.] 40 – 80 m, 5 ° 17 ' S, 145 ° 38 ' E, 3 v 1991, D. Larson (6 MCZ); Nagada River nr. Nobanob, [GE est.] 10 – 40 m, 5 ° 10 ' S, 145 ° 45 ' E, 12 vi 1991, D. Larson (10 MCZ); Ramu Valley, 6 km N Brahman, [GE est.] 130 – 150 m, 5 ° 38 ' S, 145 ° 22 ' E, 21 vi 1991, D. Larson (5 MCZ); Morobe Province: Lae – Bulolo road, ex dead leaves on mud bank, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 123) (8 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Fundextra group by the shape of the pronotum, which is subtrapezoidal, having the sides straight between the widest part and the posterior angle (Fig. 246); in other members of the group the sides are sinuate in this area. The carinate metaventral plaques are unusual in that they are higher anteriorly than posteriorly. The male genitalia distinctively differ from those of other members of the group (Fig. 248). The prosternum, meso- and metaventrite, and the abdominal apex of female are illustrated with SEMs (Figs. 376 – 379).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.36 / 0.64; head 0.19 / 0.34; pronotum 0.36 / 0.50, PA 0.37, PB 0.51; elytra 0.81 / 0.64. Dorsum of head dark brown to piceous; pronotum brown around dark brown to piceous, diffusely margined, macula, ratios of color bands, as measured in midline, ca. 7 / 13 / 4; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 xef, not notably smaller or sparser medially; interstices effacedly microreticulate, dull, 1 – 2 xpd. Clypeus effacedly microreticulate, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, not emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd of largest frons punctures, interstices strongly shining, ca. 2 – 6 xpd, punctures posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped, exceedingly shallow impression; PF 3 moderately deep, wide. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect slightly separately rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 8 / 7. P 1 very slightly wider than laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 6 / 5, sides very slightly diverging toward blunt apex. Plaques carinate lines, slightly higher anteriorly than posteriorly, parallel, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) with minute tubercle on ventral margin near basal 1 / 3; protibia arcuate in proximal 1 / 2, distal 1 / 2 slightly widened. Meso- and metatibia straight, slender. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 248).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	etymology	Etymology. " The receiving one "; named in reference to the depression between the mesocoxae, which receives the apex of the prosternal intercoxal process.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE1FF16FF79F14AFBC7FC32.taxon	distribution	Distribution. Currently known from both western and eastern arms of Area 3, and from several lowland localities in Area 5; elevation range 5 – 1100 m, but only one locality above 150 m (Fig. 544).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	description	(Figs. 247, 249, 380 – 381, 387, 548)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	materials_examined	Type Material. Holotype (male): Central Province: Port Moresby – Brown River road, ex small pool in dry gravelly stream bed, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 196) (NHM). Paratypes (12): Central Province: Loloki, 10 miles N of Port Moresby, ex swamp, much grass, [GE est.] 30 – 50 m, 9 ° 20 ' S, 147 ° 10 ' E, 19 iii 1965, M. E. Bacchus (MEB 208) (2 NHM); Moitaka, 7 miles N of Port Moresby, ex dead leaves in gravelly shallow of small pond, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 207) (2 NHM); Port Moresby – Brown River road, ex grassy shallows of large muddy pond, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 195) (2 NHM); Port Moresby – Brown River road, ex small pool in dry gravelly stream bed, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 196) (6 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	diagnosis	Differential Diagnosis. Among members of the Fundextra group, similar to H. bifunda in the plaque ratios, having P 2 slightly wider than the plaque separation (ratios ca. 5 / 1 / 8 / 4 and 5 / 1 / 6 / 4 respectively). Hydraena thola differs dorsally from H. bifunda in the following characters: the frons is strongly microreticulate, the pronotal punctures are much larger than the frons punctures, the elytral discal punctures are subserial or random, and the pronotum has a macula (Figs. 243, 247). In addition, the plaques are carinate only at the posterior extreme. The male genitalia of H. thola distinctively differs from those of other members of the group (Fig. 249). The prosternum, meso- and metaventrites, and the complicated leg chaetotaxy of the male protibia are illustrated with SEMs (Figs. 380 – 381, 387).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.42 / 0.65; head 0.21 / 0.36; pronotum 0.37 / 0.52, PA 0.40, PB 0.52; elytra 0.88 / 0.65. Dorsum of head with posterior 1 / 2 of frons dark brown, remainder of frons, clypeus, and labrum light brown to testaceous; pronotum testaceous around light brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 7 / 12 / 6; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 xef, not notably smaller or sparser medially; interstices effacedly microreticulate, dull, 0.5 – 2 xpd. Clypeus effacedly microreticulate, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc much larger than largest frons punctures, interstices strongly shining, ca. 0.5 – 2 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped impression; PF 3 moderately deep, wide. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd largest pronotal punctures, punctures subserial or random, punctures becoming gradually smaller toward posterior. Interstices not raised, weakly shining, on disc ca. 1 – 2 xpd. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 8 / 4. P 1 very slightly wider than laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 3 / 2, sides very slightly diverging toward blunt apex. Plaques very narrow lines, weakly carinate posteriorly, converging anteriorly, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) with small tubercle on ventral margin near basal 1 / 3; protibia slightly arcuate, posteromedial margin widened to form narrow ridge at about midlength. Meso- and metatibia straight, slender. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 249).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	etymology	Etymology. Named in reference to the depression between the mesocoxae.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE0FF15FF79F1DAFE44FC16.taxon	distribution	Distribution. Currently known only from a tight cluster of localities near Port Moresby, Area 11; elevation range ca. 30 – 100 m (Fig. 548).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	description	(Figs. 250, 252, 547)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Markham Valley, Gusap, c. 90 miles NW of Lae, large pond, muddy bottom with thick layer of dead leaves, dense Ceratophyllum, 305 m, 5 ° 59 ' S, 146 ° 5 ' E, 27 – 30 i 1965, M. E. Bacchus (MEB 162) (NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	diagnosis	Differential Diagnosis. Among members of the Fundextra group, similar to H. fundextra in comparatively large size (ca. 1.50 and 1.54 respectively) and in dorsal sculpture (Figs. 242, 250). Hydraena tholasoris has a pronotal fascia whereas H. fundextra has a macula. The plaque ratios differ in the two species, with H. tholasoris having shorter and less widely separated plaques compared with P 2 (ratios ca. 5 / 1 / 7 / 6 vs. 4 / 1 / 8 / 7); in addition, the plaques are anteriorly convergent in H. tholasoris and parallel in H. fundextra. The male genitalia of H. tholasoris distinctively differ from those of other members of the group (Fig. 252).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.50 / 0.67; head 0.24 / 0.37; pronotum 0.39 / 0.53, PA 0.41, PB 0.53; elytra 0.88 / 0.67. Dorsum of head dark brown; pronotum testaceous in front of and behind diffusely margined, piceous fascia, ratios of color bands, as measured in midline, ca. 6 / 15 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum very weakly shining. Frons punctures ca. 1 – 2 xef, slightly smaller and sparser medially; interstices effacedly microreticulate, dull, 0.5 – 2 xpd. Clypeus effacedly microreticulate, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc much larger than largest frons punctures, interstices strongly shining, ca. 1 – 3 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow; PF 3 moderately deep, wide. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1 / 7 / 6. P 1 slightly wider than laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 7 / 5, sides very slightly diverging toward blunt apex. Plaques narrow lines, very slightly raised posteriorly, tapering to points anteriorly, converging slightly anteriorly, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia very slightly arcuate, gradually increasing in width from base to apex, posteromedial margin with small, low carina at about midlength. Meso- and metatibia straight, slender. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 252).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	etymology	Etymology. Judging from the male genitalia this species is the sister species of H. thola.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE3FF14FF79F1F9FE50FDAA.taxon	distribution	Distribution. Currently known only from the type locality, Markham Valley, Gusap, in the eastern arm of Area 3; elevation 305 m (Fig. 547).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	description	(Figs. 251, 253, 546)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	materials_examined	Type Material. Holotype (male): East Sepik Province: Sepik, main river, 20 m, 4 ° 12 ' S, 143 ° 36 ' E, 2 iii 1965, R. W. Hornabrook (NMNZ).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Fundextra group by the condition of the carinate metaventral plaques, which diverge anteriorly; in other species of the group the plaques are either parallel or converge anteriorly (Fig. 251). The male genitalia distinctively differ from those of other members of the group (Fig. 253).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.31 / 0.50; head 0.18 / 0.33; pronotum 0.33 / 0.46, PA 0.38, PB 0.43; elytra 0.79 / 0.50. Dorsum of head dark brown; pronotum light brown around dark brown to piceous, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 6 / 12 / 5; elytra brown; legs brown; maxillary palpi testaceous, tip not darker. Dorsum very weakly shining. Frons punctures ca. 1 – 2 xef, slightly smaller and sparser medially; interstices effacedly microreticulate, dull, 0.5 – 2 xpd. Clypeus effacedly microreticulate, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate between midlength and posterior angle; punctures on disc larger and deeper than largest frons punctures, interstices strongly shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped impression; PF 3 moderately deep, wide. Elytra with posterior declivity very gradual, summit at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 8 / 6. P 1 very slightly wider than laminate; in profile, median carina nearly straight in front of coxae, behind coxae raised slightly, arcuate in profile. P 2 markedly concave, length / width ca. 5 / 4, sides very slightly converging toward blunt apex. Plaques low carinate lines, diverging slightly anteriorly, at sides of densely punctate median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin; protibia straight, ventral margin flat in distal 2 / 3. Mesotibia straight, slender. Metatibia straight, slender, medial margin emarginate in distal 3 / 4. Abdominal apex asymmetrical; last tergite (male) with deep concavity near apex, offset to left side. Aedeagus as illustrated (Fig. 253).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	etymology	Etymology. Named in honor of the collector, Richard W. Hornabrook.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE2FF14FF79F0A8FE0DF862.taxon	distribution	Distribution. Currently known only from the type locality, Sepik, main river, in the western arm of Area 3; elevation 20 m (Fig. 546).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	description	(Figs. 254, 256, 417, 551)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Okapa, under wet leaves left by receding pond, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 190) (NHM). Paratypes (28): Eastern Highlands Province: Aiyura, creek, 1670 m, 6 ° 21.131 ' S, 145 ° 54.398 ' E, 20 v 2006, John & Balke (PNG 70) (2 ZSM); Frigano, Mt. Michael, in bush stream, [GE est.] 1600 – 1700 m, 6 ° 25 ' S, 145 ° 20 ' E, 1 – 30 vii 1975, R. W. Hornabrook (2 NMNZ); Kainantu, Yoginofi, 1900 m, 6 ° 21.799 ' S, 145 ° 45.463 ' E, 9 v 2006, Balke & Sagata (PNG 55) (6 MCZ, NHM, NMW, PNG, ZSM); Okapa, under wet leaves left by receding pond, 1524 m, 6 ° 32 ' S, 145 ° 37 ' E, 10 ii 1965, M. E. Bacchus (MEB 190) (15 NHM); Madang Province: Finisterre Mts., Naho River Valley, Damanti, ex small pool, probably permanent, in clay in dense shade, 1067 m, 5 ° 55 ' S, 145 ° 58 ' E, 8 x 1964, M. E. Bacchus (MEB 39) (1 NHM); Western Highlands Province: Kurumul, 6 km SW Kudjip, 1580 m, 5 ° 53.426 ' S, 144 ° 36.6 ' E, 13 vi 2006, John (PNG 78) (2 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. photogenica (Figs. 254, 258); dorsally differing therefrom in slightly more angulate sides of the pronotum and slightly more widely rounded elytral apices. The metaventral plaques differ distinctively in the two species: in H. fundarca the plaques are more widely separated, longer, more arcuate, and markedly carinate posteriorly. In addition, P 2 is wider in H. fundarca than in H. photogenica (plaque ratios ca. 5 / 2 / 10 / 7 vs. 4 / 1 / 6 / 4). Males of H. fundarca are immediately recognized by the markedly modified protibiae and the markedly arcuate metatibiae. The male genitalia of the two species bear some general resemblance, but differ distinctively in many details (Figs. 256, 260).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.64 / 0.72; head 0.25 / 0.39; pronotum 0.39 / 0.57, PA 0.45, PB 0.54; elytra 0.98 / 0.72. Dorsum of head dark brown, clypeus and labrum slightly lighter; pronotum light brown to testaceous around brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 8 / 12 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum weakly shining. Frons punctures ca. 1 xef, smaller and sparser medially; interstices shining, 1 – 4 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides arcuate, slightly emarginate both in front of and behind widest point, more so behind; punctures on disc larger than largest frons punctures, interstices strongly shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, obsolete, nearly absent; PF 3 moderately deep, wide. Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 2 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 2 / 10 / 7. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 7 / 5, sides slightly diverging toward blunt, slightly raised apex. Plaques slightly arcuate, transversely lowly rounded anteriorly, becoming markedly carinate posteriorly, at sides of median depression. Metaventrite between mesocoxae very slightly raised. AIS width at straight posterior margin ca. 1.5 x P 2. All legs of moderate length, moderately stout. Profemur (male) with small tubercle on ventral margin near basal 1 / 3; protibia markedly modified, straight, widened on antero- and posteromedial margins forming sharp ridges, margin from widest point to apex tapering and each bearing row of short spines, medial surface concave between ridges. Mesotibia straight. Metatibia arcuate, slender, width quite uniform over total length. Abdominal apex symmetrical; last tergite (male) with apicomedian notch. Aedeagus as illustrated (Fig. 256). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 417).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	etymology	Etymology. Named in reference to the arcuate metatibiae of the males, and to the relationship to H. funda.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEDFF1AFF79F637FB61FB86.taxon	distribution	Distribution. Currently known from several localities in the eastern part of Area 1 (1524 – 1900 m), and one locality on the other side of the lowlands, in the Finisterre Mts. at the border of Areas 5 and 3 (1067 m) (Fig. 551). This is one of ten species with distributions exclusively shared between Areas 1 and 5 (Fig. 422).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	description	(Figs. 255, 257, 556)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	materials_examined	Type Material. Holotype (male): Central Province: Port Moresby – Brown River road, ex small pool in dry gravelly stream bed, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 196) (NHM). Paratypes: Same data as holotype (1 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Fundarca group by the shape of the metaventral plaques and the plaque ratios (ca. 5 / 2 / 6 / 4). This is the only species in the group that has P 2 wider than the distance between the plaques (Fig. 255). The aedeagus is very distinctive; the large lobe on the right side of the main piece is covered in velcro-like spicules in this species, whereas in the other members of the group the lobe bears short setae (Fig. 257).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.35 / 0.59; head 0.20 / 0.34; pronotum 0.34 / 0.49, PA 0.39, PB 0.47; elytra 0.83 / 0.59. Dorsum of head dark brown, clypeus and labrum slightly lighter; pronotum testaceous around dark brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 7 / 12 / 6; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and sparser medially; interstices shining, 1 – 4 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1 and PF 4 absent; PF 2 very shallow, completely shallowly confluent in midline to form U-shaped impression; PF 3 moderately deep, wide. Elytra widest at about anterior 1 / 3; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures slightly smaller than largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 4 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 2 / 6 / 4. P 1 very slightly wider than laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 6 / 5, sides very slightly diverging toward blunt, transversely slightly concave apex. Plaques slightly raised, converging, but not becoming confluent, anteriorly, at sides of inverted V-shaped median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin ca. equal P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin near basal 1 / 3; protibia slightly arcuate, gradually increasing in width from base to apex, medial margin flat. Meso- and metatibia straight, slender. Abdominal apex symmetrical; last tergite (male) with apicomedian notch. Aedeagus as illustrated (Fig. 257).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	etymology	Etymology. Named in reference to the relationship to H. funda, and to the prominent lobe of the aedeagus, which is covered with velcro-like spines.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BECFF19FF79F673FE0EFD3E.taxon	distribution	Distribution. Currently known only from the type locality near Port Moresby; this is in central Area 11, elevation 50 – 100 m (Fig. 556).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	description	(Figs. 258, 260, 553)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	materials_examined	Type Material. Holotype (male): Eastern Highlands Province: Goroka, Mt. Gahavisuka, 2200 m, 6 °. 896 ' S, 145 ° 24.753 ' E, 8 iv 2006, Balke & Sagata (PNG 35) (ZSM). Paratypes (4): Eastern Highlands Province: Same data as holotype (3 ZSM); Kainantu, Yoginofi, 1900 m, 6 ° 21.799 ' S, 145 ° 45.463 ' E, 9 v 2006, Balke & Sagata (PNG 55) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	diagnosis	Differential Diagnosis. Similar in dorsal habitus to H. fundarca (Figs. 254, 258); dorsally differing therefrom in slightly less angulate sides of the pronotum and slightly more narrowly rounded elytral apices. The metaventral plaques differ distinctively in the two species: in H. photogenica the plaques are more narrowly separated, shorter, less arcuate, and evenly carinate (plaque ratios ca. 4 / 1 / 6 / 4 vs. 5 / 2 / 10 / 7). Males of H. photogenica lack the markedly modified pro- and metatibiae present in H. fundarca. The male genitalia of the two species bear some general resemblance, but differ distinctively in many details (Figs. 256, 260).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.56 / 0.67; head 0.23 / 0.36; pronotum 0.39 / 0.55, PA 0.42, PB 0.50; elytra 0.94 / 0.67. Dorsum of head with frons dark brown to piceous, clypeus brown, labrum light brown to testaceous; pronotum light brown around dark brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 8 / 12 / 6; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum shining. Frons punctures ca. 1 xef near eyes, smaller and much sparser medially; interstices shining, 1 – 5 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 5 xpd, punctures anteriorly and posteriorly very slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 1 / 6 / 4. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 3 / 2, sides very slightly diverging toward blunt, slightly concave apex. Plaques low carinate lines, converging anteriorly, at sides of median depression. Metaventrite flat between mesocoxae. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) with very small tubercle on ventral margin near basal 1 / 3; protibia straight, medial margin slightly widened in distal 1 / 2. Meso- and metatibia straight, slender. Abdominal apex symmetrical; last tergite (male) with apicomedian notch. Aedeagus as illustrated (Fig. 260).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	etymology	Etymology. A photogenic species (see Fig. 258).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEFFF18FF79F0D1FE43FEF2.taxon	distribution	Distribution. Currently known from two moderately closely spaced localities in eastern Area 1; elevations 1900 m and 2200 m (Fig. 553).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	description	(Figs. 259, 261, 554)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Torricelli Mts., village below Sibilanga Stn., 400 m, 3 ° 26.75 ' S, 142 ° 29.949 ' E, 18 iv 2006, Balke (PNG 42) (ZSM). Paratype: Same data as holotype (1 female ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	diagnosis	Differential Diagnosis. Differentiated from other members of the Fundarca group by the testaceous pronotum, which has the anterior margin very weakly produced in the middle (Fig. 259). The form of the aedeagus and the shape of the male abdominal apex clearly suggest that this species is allied with the putative sister species pair H. fundacta and H. johncoltranei. In addition to the testaceous pronotum, H. torricellica differs from the compared species by the carinate metaventral plaques, and the transversely concave intercoxal process of the metaventrite. The male genitalia of the three species distinctively differ in many details (Figs. 261, 264, 265).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.45 / 0.63; head 0.24 / 0.35; pronotum 0.38 / 0.50, PA 0.38, PB 0.48; elytra 0.87 / 0.63. Dorsum of head with frons dark brown to piceous, clypeus brown, labrum testaceous; pronotum testaceous; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, much smaller and much sparser medially; interstices shining, 1 – 6 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, anterior margin very weakly bisinuate, very weakly produced in middle, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow, wide. Elytra widest at about midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 3 / 8. P 1 laminate; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. equal, sides very slightly diverging toward blunt, slightly concave apex. Plaques very short, widely separated, carinate lines, converging anteriorly, at sides of median depression. Metaventrite between mesocoxae slightly sloping, transversely concave, confluent with tip of P 2. AIS width at straight posterior margin ca. equal P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin near basal 1 / 3; protibia straight, posteromedial margin very slightly widened to form narrow ridge at about midlength, medial margin weakly concave. Meso- and metatibia straight, slender. Abdominal apex (male) enlarged, asymmetrical; last tergite with oblique ridge on dorsal surface. Aedeagus as illustrated (Fig. 261).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	etymology	Etymology. Named in reference to the geographical distribution.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEEFF18FF79F39AFEEDF8DD.taxon	distribution	Distribution. Currently known only from the type locality in the Torricelli Mts.; this is in Area 4, elevation 400 m (Fig. 554).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	description	(Figs. 262, 264, 552)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Adelbert Mts., Sewan – Keki, 700 m, 4 ° 42.215 ' S, 145 ° 25.154 ' E, 4 v 2006, Balke & Manaono (PNG 51) (ZSM). Paratypes (32): Madang Province: Same data as holotype (20 MCZ, NHM, NMW, PNG, ZSM); Adelbert Mts., below Keki, 790 m, 4 ° 42.3 ' S, 145 ° 25.089 ' E, 5 v 2006, Balke & Manaono (PNG 53) (2 ZSM); Sandaun Province: Bewani Stn., limestone creek at base of Bewani Mts., 400 m, 3 ° 5.13 ' S, 141 ° 10.227 ' E, 12 iv 2006, Balke & Sagata (PNG 39) (3 ZSM); road Vanimo – Bewani close coast, 400 – 480 m, 2 ° 44.372 ' S, 141 ° 15.067 ' E, 13 iv 2006, Balke & Sagata (PNG 41) (7 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	diagnosis	Differential Diagnosis. The putative sister species of H. johncoltranei (Figs. 262, 263); refer to the differential diagnosis of that species.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.30 / 0.57; head 0.18 / 0.32; pronotum 0.33 / 0.49, PA 0.37, PB 0.43; elytra 0.77 / 0.57. Dorsum of head dark brown, clypeus and labrum slightly lighter; pronotum testaceous around dark brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 7 / 12 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, smaller and slightly sparser medially; interstices weakly shining, 1 – 2 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and weakly shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc ca. 1 xpd largest frons punctures, interstices shining, ca. 2 – 3 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow, wide. Elytra widest slightly anterior to midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 2 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another. P 1 slightly wider than laminate; median carina nearly straight in profile, slightly arcuate between coxae. P 2 markedly concave, length / width ca. equal, sides parallel, apex blunt, not concave. Plaques absent. Metaventrite flat or very slightly convex between mesocoxae. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) with very small tubercle on ventral margin near basal 1 / 3; protibia very slightly arcuate, width quite uniform in distal 3 / 4. Meso- and metatibia straight, slender. Abdominal apex (male) enlarged, asymmetrical; last tergite with oblique ridge on dorsal surface. Aedeagus as illustrated (Fig. 264).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	etymology	Etymology. Named in reference to the geographical distribution near the ocean, and membership in the Fundarca group.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1FFF79F2BAFF67F9BD.taxon	distribution	Distribution. The only species exclusive shared between Areas 4 and 5; elevation range 400 – 790 m (Fig. 552).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	description	(Figs. 263, 265, 555)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	materials_examined	Type Material. Holotype (male): National Capital District, Varirata NP, 600 m, 9 ° 26.13 ' S, 147 ° 22.09 ' E, 16 xii 2007, Balke & Sagata (PNG 159) (ZSM). Paratypes (10): Madang Province: Keki – Sewan, Adelbert Mts., 700 m, 4 ° 41.802 ' S, 145 ° 25.46 ' E, 30 xi 2006, Binatang Boys (PNG 120) (4 ZSM); National Capital District, Same data as holotype (6 MCZ, NHM, NMW, PNG, ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	diagnosis	Differential Diagnosis. Very similar to and, based on the male genitalia, the sister species of, H. fundacta (Figs. 262, 263). Both species are differentiated from other members of the Fundarca group by the metaventral plaques, which are either reduced to tiny oval bumps (H. johncoltranei), or totally absent (H. fundacta). In addition, both species have P 1 slightly wider than laminate, and, in males, the abdominal apex is modified. The male genitalia of each species have a greatly enlarged basal ring; the distal piece, while similar in basic plan, has distinct differences in the two species (Figs. 264, 265).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.33 / 0.59; head 0.18 / 0.33; pronotum 0.34 / 0.49, PA 0.36, PB 0.45; elytra 0.80 / 0.59. Dorsum of head with frons and clypeus dark brown to piceous, labrum testaceous; pronotum light brown to testaceous around dark brown to piceous, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 6 / 12 / 5; elytra brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef near eyes, slightly smaller and sparser medially; interstices shining, 2 – 3 xpd. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate and shining medially. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, except margin very weakly produced in middle, sides weakly arcuate, slightly emarginate between midlength and posterior angle; punctures on disc slightly larger than largest frons punctures, interstices shining, ca. 2 – 4 xpd, punctures anteriorly and posteriorly slightly larger than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow, wide. Elytra widest slightly anterior to midlength; summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1 / 3 punctures ca. 1 xpd of largest pronotal punctures, but shallower, a few punctures subserial, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 4 / 0.5 / 1 / 6. P 1 0.5 x P 2; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length / width ca. 5 / 4, sides very slightly diverging toward blunt, slightly concave apex. Plaques minute, nearly imperceptible bumps, at sides of median depression. Metaventrite between mesocoxae slightly sloping, confluent with tip of P 2. AIS width at straight posterior margin slightly greater than P 2. All legs of moderate length. Profemur (male) without tubercle on ventral margin near basal 1 / 3; protibia very slightly arcuate, slender, gradually increasing in width from base to apex. Meso- and metatibia straight, slender. Abdominal apex (male) enlarged, asymmetrical; last tergite with oblique ridge on dorsal surface. Aedeagus as illustrated (Fig. 265).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	etymology	Etymology. Named in honor of the jazz great, the supreme saxophonist John Coltrane.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BE9FF1EFF79F453FC99FA9A.taxon	distribution	Distribution. A very disjunct and curious distribution: one locality each in the Adelbert Mts. (Area 5, 700 m), and the Varirata National Park (Area 11, 600 m) (Fig. 555).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	description	(Figs. 266, 268, 364 – 368, 418, 549)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Lae – Bulolo road, ex dead leaves on mud bank, [GE est.] 900 – 1100 m, 6 ° 52 ' S, 146 ° 37 ' E, 28 xii 1964, M. E. Bacchus (MEB 123) (NHM). Paratypes (75): Morobe Province: Same data as holotype (74 NHM); Huon Pen., road to Kwapsanek, 250 m, 6 ° 30.27 ' S, 146 ° 59.581 ' E, 31 iii 2006, Balke & Sagata (PNG 24) (1 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	diagnosis	Differential Diagnosis. Very similar in dorsal habitus and ventral structures to H. herzogestella, the other member of the Fenestella group (Figs. 266, 267); differing therefrom in smaller size (ca. 1.22 vs. 1.32 mm) and in plaque ratios (ca. 5 / 1.5 / 5 / 4 vs. 6 / 1 / 6 / 5). Reliable determinations will require careful examination of the male genitalia (Figs. 268, 269). The meso- and metaventrite, pronotum, and very complicated chaetotaxy of the protibiae are illustrated with SEMs (Figs. 364 – 368).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.22 / 0.58; head 0.20 / 0.32; pronotum 0.32 / 0.47, PA 0.36, PB 0.47; elytra 0.72 / 0.58. Dorsum of head with frons brown, clypeus and labrum testaceous; pronotum testaceous, semi-transparent; elytra brown; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Dorsum shining. Frons punctures ca. 1 xef near eyes, smaller and much sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 4 – 6 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining. Postmentum anteriorly finely punctate, posteriorly moderately coarsely punctate, shining. Genae flat or very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, side very slightly emarginate between anterior angle and midlength; punctures on disc ca. 1 xpd of largest frons punctures, interstices strongly shining, ca. 1 – 4 xpd; PF 1, PF 2 and PF 4 absent; PF 3 shallow. Elytra with posterior declivity very gradual, summit slightly anterior to midlength; lateral explanate margins narrow. Punctures very small, shallow, ca. 1 xpd pronotal punctures, and widely spaced. Intervals shining, ca. 3 – 5 xpd or greater. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 5 / 1.5 / 5 / 4. P 1 ca. 1 / 3 P 2; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length ca. equal width, sides slightly converging toward blunt apex. Plaques roundly slightly raised, converging but not joining anteriorly, at sides of inverted Vshaped median depression. Metaventrite conjointly concave with P 2 between mesocoxae. AIS width at straight posterior margin ca. equal P 2. All legs of moderate length, tibiae very slender. Profemur (male) without tubercle next to trochanter; protibia arcuate, especially in basal 1 / 2, gradually increasing in width from base to distal 1 / 3, then slightly narrowing to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) sharply rounded. Aedeagus as illustrated (Fig. 268). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 418).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	etymology	Etymology. " Little window "; named in reference to the transparency of the pronotum.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1DFF79F2BAFB05F991.taxon	distribution	Distribution. Currently known only from two localities somewhat near Lea; one at the eastern extreme of Area 3 (900 – 1100 m), and one on the southern part of the Huon Peninsula (250 m) (Fig. 549).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	description	(Figs. 267, 269, 550)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	materials_examined	Type Material. Holotype (male): Morobe Province: Herzog Mts., Bundun, 700 – 800 m, 6 ° 51.598 ' S, 146 ° 37.07 ' E, 2 iv 2006, Balke & Sagata (PNG 27) (ZSM). Paratypes: Same data as holotype (3 ZSM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	diagnosis	Differential Diagnosis. Very similar in dorsal habitus and ventral structures to the other member of the Fenestella group, H. fenestella (Figs. 266, 267); differing therefrom in larger size (ca. 1.32 vs. 1.22 mm) and in plaque ratios (ca. 6 / 1 / 6 / 5 vs. 5 / 1.5 / 5 / 4). Reliable determinations will require careful examination of the male genitalia (Figs. 268, 269).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.32 / 0.61; head 0.18 / 0.34; pronotum 0.34 / 0.50, PA 0.38, PB 0.50; elytra 0.83 / 0.61. Dorsum of head with frons dark brown, clypeus and labrum brown; pronotum testaceous; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker. Dorsum shiny. Frons punctures ca. 1 xef near eyes, smaller and much sparser medially; interstices shining, 1 – 2 xpd laterally, ca. 2 – 8 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctulate medially. Mentum and postmentum virtually impunctate, very sparsely very finely punctulate, shining. Genae flat or very slightly raised, shining, without posterior ridge. Pronotum subtrapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, side very slightly emarginate between anterior angle and midlength; punctures on disc ca. 1 – 2 xpd of largest frons punctures, interstices strongly shining, ca. 2 – 6 xpd; PF 1 absent, PF 2 very shallow, obsolete, completely confluent to form one transverse impression, PF 3 shallow, PF 4 absent. Elytra with posterior declivity very gradual, summit slightly anterior to midlength; lateral explanate margins narrow. Punctures very small, shallow, ca. 1 xpd pronotal punctures, and widely spaced. Intervals shining, ca. 3 – 5 xpd or greater. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 6 / 1 / 6 / 5. P 1 ca. 1 / 3 P 2; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 markedly concave, length ca. 5 / 6 width, sides slightly diverging toward blunt apex. Plaques roundly slightly raised, slightly converging anteriorly, at sides of median depression. Metaventrite between mesocoxae slightly concave, conjointly with P 2. AIS width at straight posterior margin ca. 5 / 6 P 2. All legs of moderate length, tibiae very slender. Profemur (male) with minute sharp tubercle on medial margin near midlength; protibia arcuate, especially in basal 1 / 2, gradually increasing in width from base to distal 1 / 3, then slightly narrowing to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) with small apicomedian notch. Aedeagus as illustrated (Fig. 269).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	etymology	Etymology. Name in reference to the geographical distribution and the relationship to H. fenestella.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEBFF1CFF79F477FE57FC7A.taxon	distribution	Distribution. Currently known only from the type locality, Bundun, Herzog Mts.; this is placed in Area 6, elevation 700 – 800 m (Fig. 550).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	description	(Figs. 270, 272, 419, 538)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	materials_examined	Type Material. Holotype (male): Madang Province: Ramu Valley, 3 km N Brahman, [GE est.] 130 – 150 m, 5 ° 40 ' S, 145 ° 22 ' E, 16 v 1991, D. Larson (MCZ). Paratypes (131): East Sepik Province: Amboin Patrol Post, Karawari Lodge, [GE est.] 20 – 100 m, 4 ° 37 ' S, 143 ° 29 ' E, 7 ii 1983, A. C. Messer (4 USNM); same locality, 26 iii 1983, A. C. Messer (2 USNM); Madang Province: Adelbert Mts., Keki to Sewan, 650 m, 4 ° 41.802 ' S, 145 ° 25.46 ' E, 7 v 2006, Balke (PNG 54) (9 MCZ, NHM, NMW, PNG, ZSM); Akameku – Brahmin, Bismarck Range, 250 – 500 m, 5 ° 47.026 ' S, 145 ° 24.131 ' E, 25 xi 2006, Balke & Kinibel (PNG 115) (12 MCZ, NHM, NMW, PNG, ZSM); Baiteta, [GE est.] 100 – 200 m, 5 ° 1 ' S, 145 ° 45 ' E, 13 iii 1991, D. Larson (5 MCZ); Keki, Adelbert Mts., 400 m, 4 ° 43.058 ' S, 145 ° 24.437 ' E, 29 xi 2006, Binatang Boys (PNG 119) (6 MCZ, NHM, NMW, PNG, ZSM); near Brahmin, 200 m, 5 ° 47.026 ' S, 145 ° 24.131 ' E, 25 xi 2006, Balke & Kinibel (PNG 116) (7 MCZ, NHM, NMW, PNG, ZSM); Ramu Valley, 3 km N Brahman, [GE est.] 130 – 150 m, 5 ° 40 ' S, 145 ° 22 ' E, 16 v 1991, D. Larson (32 MCZ); Morobe Province: Torricelli Mts., village below Sibilanga Stn., 400 m, 3 ° 26.75 ' S, 142 ° 29.949 ' E, 18 iv 2006, Balke (PNG 42) (6 MCZ, NHM, NMW, PNG, ZSM); National Capital District, Varirata NP, 600 m, 9 ° 26.13 ' S, 147 ° 22.09 ' E, 16 xii 2007, Balke & Sagata (PNG 159) (22 MCZ, NHM, NMW, PNG, ZSM); Sandaun Province: Bewani Stn., forest puddles at base of Bewani Mts., 300 m, 3 ° 5.13 ' S, 141 ° 10.227 ' E, 12 iv 2006, Balke & Sagata (PNG 38) (15 MCZ, NHM, NMW, PNG, ZSM); Bewani Stn., stream at base of Bewani Mts., 200 – 300 m, 3 ° 5.13 ' S, 141 ° 10.227 ' E, 12 iv 2006, Balke & Sagata (PNG 37) (7 MCZ, NHM, NMW, PNG, ZSM); Mianmin, river, 1080 m, 4 ° 55.78 ' S, 141 ° 38.185 ' E, 24 x 2008, S. Ibalim (PNG 195) (2 ZSM); road Vanimo – Bewani close coast, 400 – 480 m, 2 ° 44.372 ' S, 141 ° 15.067 ' E, 13 iv 2006, Balke & Sagata (PNG 41) (1 ZSM); Telefomin, trail to Eliptamin, 1700 – 1800 m, 5 ° 4 ' S, 141 ° 40 ' E, 16 – 17 v 1998, A. Riedel (1 NMW).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	diagnosis	Differential Diagnosis. Recognized by the combination of the large size (l / w ca. 1.82 / 0.86 mm), the broad body form, the basally wide pronotum (PA / PB as ca. 49 / 67), and, in males, the greatly enlarged abdominal apex (Fig. 270). Ventrally, P 2 is very wide and concave, and the metaventral plaques are carinate and equally widely separated (plaque ratios ca. 8 / 1 / 7 / 8). The male genitalia cannot be confused with any other PNG Hydraena (Fig. 272).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.82 / 0.86; head 0.25 / 0.44; pronotum 0.46 / 0.67, PA 0.49, PB 0.67; elytra 1.12 / 0.86. Dorsum of head with frons dark brown to piceous, clypeus brown medially, testaceous laterally, labrum testaceous; pronotum testaceous around brown, diffusely margined, rectangular macula, ratios of color bands, as measured in midline, ca. 9 / 15 / 7; elytra dark brown; legs brown to light brown; maxillary palpi testaceous, tip not darker. Dorsum moderately shining. Frons punctures ca. 1 xef or slightly smaller near eyes, much smaller and sparser medially; interstices shining, 1 – 5 xpd. Clypeus very finely sparsely punctulate, shining. Mentum very sparsely very finely punctulate, shining. Postmentum effacedly microreticulate in shallow median depression, otherwise finely sparsely punctate. Genae very slightly raised, shining, with shallow, obsolete median impression, without posterior ridge. Pronotum transverse, ca. median 3 / 4 of anterior margin slightly arcuate to posterior, sides weakly arcuate, slightly emarginate in front of and behind widest part; punctures on disc ca. 2 – 3 xpd largest frons punctures, interstices shining, ca. 1 – 3 xpd, punctures posteriorly slightly larger and denser than those on disc; PF 1, PF 2 and PF 4 absent; PF 3 shallow, wide. Elytra widest at about anterior 1 / 3; summit of posterior declivity at or very near midlength; lateral explanate margins rather narrow; on basal 1 / 3 punctures slightly smaller and shallower than largest pronotal punctures, subserial to random, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1 – 3 xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming deep angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 8 / 1 / 7 / 8. P 1 slightly wider than laminate, ca. 1 / 4 P 2; median carina nearly straight in profile, slightly arcuate between coxae. P 2 markedly concave, length / width ca. 5 / 8, sides very slightly diverging toward blunt, transversely concave apex. Plaques narrow lines, anteriorly flat or weakly rounded, becoming low carinae posteriorly, converging anteriorly, at sides of median inverted V-shaped depression. Metaventrite between mesocoxae sloping, confluent with concave tip of P 2. AIS width at slightly arcuate posterior margin ca. equal P 2. All legs of moderate length, slender. Profemur (male) without tubercle on ventral margin; protibia straight, distal 2 / 3 of medial margin very slightly emarginate and flat. Meso- and metatibia straight, slen- der. Abdominal apex greatly enlarged, pygidiform, asymmetrical; last tergite (male) with oblique subapical ridge at margin of concavity. Aedeagus as illustrated (Fig. 272). Female tergite X, gonocoxite, and spermatheca as illustrated (Fig. 419).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	etymology	Etymology. Named in reference to the very large, peg-shaped abdominal apex.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BEAFF03FF79F41BFCB1F8BE.taxon	distribution	Distribution. Widely distributed both horizontally and vertically, but apparently very sparsely as far as is known. Localities are present in Areas 1 – 5, and Area 11; elevation range 20 – 1800 m (Fig. 538). This is the only species that has been found in both Area 4 and Area 11.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	description	(Figs. 271, 273, 370 – 372, 560)	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	materials_examined	Type Material. Holotype (male): Central Province: Moitaka, 7 miles N of Port Moresby, ex dead leaves in gravelly shallow of small pond, [GE est.] 30 – 50 m, 9 ° 25 ' S, 147 ° 12 ' E, 17 iii 1965, M. E. Bacchus (MEB 207) (NHM). Paratypes (10): Central Province: Same data as holotype (4 NHM); Port Moresby – Brown River road, ex grassy shallows of large muddy pond, [GE est.] 50 – 100 m, 9 ° 24 ' S, 147 ° 14 ' E, 15 iii 1965, M. E. Bacchus (MEB 195) (6 NHM).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	diagnosis	Differential Diagnosis. Differentiated from other PNG members of the genus by the combination of very small size (ca. 1.16 mm), trapezoidal pronotum, and extremely finely punctate dorsum (Fig. 271). The male genitalia distinctly differ from those of other PNG Hydraena, but are quite similar to the genitalia of the Australian species H. trapezoidalis (Fig. 273). The prosternum, meso- and metaventrite, abdominal apex of female, and complicated chaetotaxy of the protibiae are illustrated with SEMs (Figs. 370 – 372).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	description	Description. Size: holotype (length / width, mm): body (length to elytral apices) 1.16 / 0.51; head 0.18 / 0.30; pronotum 0.29 / 0.44, PA 0.33, PB 0.44; elytra 0.69 / 0.51. Dorsum of head dark brown to dark reddish brown; pronotum light brown to testaceous around dark brown, rectangular macula on disc, ratios of color bands, as measured in midline, ca. 5 / 10 / 4; elytra dark brown, with interstices lighter than columellae; legs light brown to testaceous; maxillary palpi testaceous, tip not darker. Dorsum very shiny. Frons punctures ca. 1 xef, larger and denser near eyes than medially; interstices shining, 1 – 2 xpd laterally, ca. 4 – 8 xpd medially. Clypeus effacedly microreticulate laterally, very finely sparsely punctate medially. Mentum very sparsely very finely punctulate, shining. Postmentum anteriorly finely punctate, posteriorly moderately coarsely punctate, shining. Genae flat or very slightly raised, shining, without posterior ridge. Pronotum trapezoidal, ca. median 3 / 4 of anterior margin slightly arcuate to posterior; punctures on disc extremely fine and sparse, usually smaller than smallest frons punctures, interstices strongly shining, ca. 5 – 10 xpd or more; PF 1, PF 2 and PF 4 absent; PF 3 moderately deep, obsolete, large. Elytra with summit of weak posterior declivity slightly posterior to midlength; lateral explanate margins narrow. Punctures very small, shallow, and widely spaced, for the most part not forming discrete series. Intervals strongly shining. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another. Ratios of P 2 width and plaque shape (P 2 / w / l / s) ca. 2 / 2 / 3 / 6. P 1 ca. 1 / 2 P 2; median carina nearly straight in profile, very slightly arcuate between coxae. P 2 transversely slightly concave, length ca. 2 x width, sides slightly converging toward blunt, non-raised apex. Plaques roundly slightly raised, converging anteriorly, at sides of inverted V-shaped median depression. Metaventrite not concave between P 2 and plaques. AIS width at straight posterior margin ca. 2 x P 2. All legs of moderate length, tibiae very slender. Profemur (male) without tubercle next to trochanter; protibia very slightly arcuate, gradually increasing in width from base to apex. Meso- and metatibia straight. Abdominal apex symmetrical; last tergite (male) sharply rounded. Aedeagus as illustrated (Fig. 273).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	etymology	Etymology. " Base, bottom "; named in reference to the wide pronotal base.	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
03B087E55BF4FF01FF79F614FE10FDC9.taxon	distribution	Distribution. Currently known from two very narrowly separated localities near Port Moresby (Area 11), elevation ca. 30 – 100 m (Fig. 560). This is the putative sister species of H. trapezoidalis, which is distributed in northern Australia (Fig. 559).	en	Perkins, Philip D. (2011): New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944. Zootaxa 2944 (1): 1-417, DOI: 10.11646/zootaxa.2944.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2944.1.1
