taxonID	type	description	language	source
03FD136EB94BA93FFED5EEA4FCDDFD90.taxon	diagnosis	Diagnosis. Body variously oval, rather flat to strongly convex; pronotum and elytra forming a continuous curve in lateral view. Dorsal surface glabrous, with punctation and sometimes with microsculpture or indistinct pubescence; pronotum without longitudinal grooves or pit-like impressions except often with 2 lateroposterior depressions; color ranging from pale yellow to black. Ventral surface covered in dense, short pubescence except raised surfaces of meso- and metaventrites. Antennae 9 - segmented, terminal 3 antennomeres forming compact club; bases visible dorsally, not hidden by lateral margin of head. Clypeus not separated from frons by a distinct suture, often truncate, extending anterior to eyes when viewed dorsally; mentum of variable shape, anterior margin subtruncate or emarginate, often impressed anteromedially. Maxillary palpi shorter than antennae, 2 nd palpomere swollen apically, length of apical segment equal to or slightly longer than penultimate; male maxilla bearing adhesion discs, though may be indistinct in smaller species. Elytra with distinct epipleura, at least in basal half. Middle portion of prosternum elevated to form a tectiform longitudinal keel, not differentiated laterally from antennal excavations. Median portion of mesoventrite elevated to form a median keel or plate; contacting metaventrite at a single point or separated from it by a narrow gap. Outer margin of profemora rounded; tarsal formula 5 - 5 - 5 with 1 st tarsomere always longer than 2 nd. Male genitalia of trilobed type, as in Fig. 7. Female genitalia as in Fig. 13. Notes on Identification. Along with members of the Staphylinidae, Cercyon is one of the more common beach-dwelling beetle taxa. As it is the only beach-dwelling hydrophilid genus in most regions, excluding Australia and New Zealand, it can be easily differentiated from other beach beetles by its evenly oval habitus, uninterrupted outline between pronotum and elytra, presence of a mesoventral tablet, maxillary adhesion discs, and clubbed antennae.	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	description	Description. Body length = 2.1 – 4.2 mm, width = 1.7 – 2.9 mm; body oval, convex though dorsoventrally compressed (Figs. 1 A, B, 5 A), body outline continuous between pronotum and elytra. Surface shiny anteriorly, becoming matte, rugose on posterior half of elytra; head piceous; pronotum and elytra irregularly piceous to testaceous with lateral and posterior margins pale, variegated; base of elytra often with pale spots, elytral suture often dark. Ventrally piceous with white pubescence; femora testaceous or fulvous. Head covered with dense punctures separated by a little more than their diameter except a narrow space around epicranial suture; interspaces with dense, granulate microsculpture except along median line and posterolateral to epicranial sutures, clypeus anteriorly truncate with marginal stria, anterior margins rounded (Fig. 5 B). Eyes separated by about 9 X their width dorsally. Mentum trapezoidal (length: width index = 0.46); anterior margin carinate; surface slightly convex; covered in uniform, dense granulate microsculpture and setae on posterior half and around to anterolateral margins. Maxillary palpi a little longer than half width of head; second palpomere swollen apically, about 2 X as long as wide; apical palpomere fusiform, a little longer than penultimate. Male with adhesion disks on maxillae, diameter a little over 1 / 5 width of mentum (Fig. 5 C). Antenna about 0.85 X width of head; pedicel about 1 / 5 length of scape; club compact, about 2 X as long as wide. Pronotum widest at base, lateral margins evenly rounded; surface covered with dense punctures separated by about their diameter; very sparse, minute microsculpture only visible at high magnification (Fig. 5 A, D). Elytra with sides regularly curved, widest at about the middle; with 10 relatively superficial striae, becoming less impressed posteriorly and laterally. Intervals flat, with dense punctures separated by about their diameter, interspaces with dense granulate microsculpture and sparse microrugae, though absent on anteromedial disk of elytra. Prosternum weakly tectiform, with or without complete carina medially, with grooves for reception of antennal club, pubescent, not reaching lateral margin. Mesoventral tablet extremely narrow, almost linear (length: width index = 7.3 – 13.0); surface flat, shiny, with fine punctures (Fig. 5 E, F). Metaventrite with raised pentagonal plate, convex, shiny, punctate, punctures separated by about 2 – 3 X their diameter, interspaces in anteromedial area sometimes with weak granulate microsculpture, projecting anteriorly between mesocoxae and contacting mesoventral tablet at a single point; lateral portions densely pubescent, lacking punctures or femoral lines (Fig. 5 E). Femora punctate, punctures separated by 2 – 3 X their diameter; interspaces with indistinct to dense granulate microsculpture. Tibia with dense granulate microsculpture. Aedeagus as in Fig. 7 A – C; median lobe roundly narrowed to apex, apical third with short, dense setae, parameres narrow (genital ratio = 1.01).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	materials_examined	Type Material. Holotype male: CANADA: British Columbia, Big Beach, Ucluelet, 48.93500 ° N, 125.55250 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 025, pinned, with genitalia preserved in Canada balsam. Paratypes: Canada, British Columbia, Vancouver Isle: Otter Point, Sooke, 48.39667 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 007 (1 sex undetermined); Sombrio Beach, Juan de Fuca, 48.49810 ° N, 124.30000 ° W, M. Ôhara, 2014. VI. 27, BC 14 MO- 010 (2 males); Little Beach, Ucluelet, 48.93389 ° N, 125.54056 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 023 a (1 male); Big Beach, Ucluelet, 8.93500 ° N, 125.55250 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 025 (5 males, 2 females); “ Bowser, B. C. / VI. 8: - 55 / W. J. Brown // C. luniger Mannerheim / Det. M. Hatch ” OSAC _ 0000186121 – OSAC _ 186126 (4 males, 1 sex undetermined); USA: Washington. Whisky Creek Beach, Port Angeles, Clallam Co., 48.15557 ° N, 123.780673 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 008 (9 males, 9 females); Chito Beach Resort, Sekiu, Clallam Co., 48.305656 ° N, 124.428559 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 009 (6 sex undetermined); unnamed beach, Sekiu, Clallam Co., 48.345279 ° N, 124.17207 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 010 (4 males, 1 female); Hobuck Beach, Neah Bay, Makah Reservation, 48.336265 ° N, 124.663221 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 011 (1 sex undetermined); Derelict Conveyor, Ferndale, Whatcom Co., 48.855832 ° N, 122.72963 ° W, A. Suzumura, 2018. VIII. 28, WA 18 AS- 015 (1 male, 1 female). Holotype deposited in BBM with six paratypes (BC 14 MO- 007, 1 specimen; BC 14 MO- 010, 1 specimen; BC 14 MO- 023 a, 1 specimen; BC 14 MO- 025, 3 specimens). Six paratypes will be deposited in MCZ (WA 18 AS- 008, 6 specimens) and five in OSAC (OSAC _ 0000186121 – OSAC _ 0000186126, 5 specimens). The remaining paratypes will be deposited in SEHU (BC 14 MO- 010, 1 specimen; BC 14 MO- 25, 3 specimens, WA 18 AS- 008, 12 specimens; WA 18 AS- 010, 5 specimens; WA 18 AS- 011, 1 specimen; WA 18 AS- 015, 2 specimens).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	distribution	Distribution. British Columbia and Washington State.	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	etymology	Etymology. “ whulj ” from the Lushootseed language means “ salt water ” and is the original name for the Salish Sea, a complex network of waterways extending from southwestern British Columbia through northwestern Washington State and the type locality for this species.	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	discussion	Remarks. Cercyon whuljensis is similar to C. luniger and often found living with it (Smetana 1978) but differs in the vastly different shape of the male parameres, absence of a small area of microsculpture on the apical angles of the pronotum, and darker, more mottled coloration. Due to close external similarities, several specimens of C. whuljensis were previously identified by M. H. Hatch (OSAC _ 00000186121 - 00000186126) as C. luniger, but examination of the lectotype (GAC. 28090) and one paralectotype (MCZ- ENT 00007930) of C. luniger revealed that the specimens Hatch identified are in fact a previously undescribed species. The genitalia illustrated as belonging to C. luniger in Smetana (1988) corresponds to C. whuljensis, whereas the genitalia of C. spathifer in Smetana (1978) corresponds to the true C. luniger. Cercyon (Cercyon) dux Sharp, 1873 (Figs. 1 C, D, 2 B, 4 A, C, 7 D – F, 8)	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	description	Jia 2006: 2. Redescription. Body length = 3.5 – 5.0 mm, width = 2.1 – 2.8 mm; body oval, outline slightly interrupted between pronotum and elytra, convex (Figs. 1 C, D, 8 A); shiny with dense punctation, no microsculpture dorsally. Color patterns as follows: 1) head piceous, pronotum and elytra piceous to testaceous, fulvous along lateral area, though often not reaching margin, often paler along elytral suture and striae (Fig. 1 C, D); 2) head, pronotum, and scutellum piceous, lateral margins of pronotum often paler, elytra testaceous. Ventrally piceoustestaceous with white pubescence, legs testaceous. Head covered with dense punctures separated by a little less than their diameter except a narrow area around epicranial sutures; clypeus truncate with marginal striae (Fig. 8 B). Eyes large, separated by about 6 X their width dorsally. Mentum trapezoidal (length: width index = 1.79), anterior margin carinate, deeply impressed anteromedially, male mentum evenly covered with a dense patch of seate (Fig. 8 C), female mentum punctate, interspaces filled with granulate microsculpture. Length of maxillary palpi about 0.5 X width of head; 2 nd palpomere swollen apically, about 2.5 X as long as wide; apical palpomere fusiform, about as long as penultimate. Male with large adhesion disks on maxillae, diameter about half width of mentum (Fig. 8 C). Length of antenna a little less than width of head, pedicel about 1 / 3 length of scape, club compact, a little less than 2 X as long as wide. Pronotum widest about 1 / 3 before base; lateral margins strongly convex, evenly rounded; surface covered with very dense punctures separated by a little less than their diameter. Elytra with sides regularly curved, widest at about middle; with 10 striae, deeply impressed posteriorly, 10 th stria superficial, pigmented but not impressed; intervals convex with dense punctures separated by less than their diameter (Fig. 8 D); without pubescence. Pseudepipleura almost horizontal; epipleura densely pubescent. Prosternum tectiform, carinate medially; with welldefined grooves for reception of antennal club; pubescent. Mesoventral tablet narrowly triangular, widest posteriorly and narrowed anteriorly (length: width index = 5.3 – 8.0), surface shiny, densely punctate, flat though anterior 1 / 7 depressed (Fig. 8 E, F). Metaventrite with raised pentagonal plate, convex, shiny, and densely punctate; projecting anteriorly between mesocoxae and almost contacting posterior margin of mesoventral plate, lateral portions densely pubescent, lacking punctures or femoral lines (Fig. 8 E). Metepisterna rectangular, parallel, about 5 X as long as wide. Femora densely punctate with punctures separated by about 2 – 3 X their diameter, interspaces on meso- and metafemora with indistinct to dense granulate microsculpture. Tibiae with fine rugose microsculpture. Aedaegus as in Fig. 7 D – F, median lobe wide, with opening at about 1 / 3 from apex, rounded and with dense setae from opening to tip; parameres wide, diagonally weakly tapered to diagonally truncate apices (genital ratio = 0.92). Specimens Examined. CANADA: British Columbia. Vancouver Isle: Cowichan Bay, near Dancan, 48.740556 ° N, 123.941667 ° W, M. Ôhara, 2014. VI. 28, BC 14 MO- 012 (1 sex undetermined); Connox Bay, Royston, 49.64917 ° N, 125.94417 ° W, M. Ôhara, 2014. VII. 2, BC 14 MO- 027 (1 male, 4 females); Arbutus Grove Provincial Park, Nanoose Bay, 49.26194 ° N, 124.18889 ° W, M. Ôhara, 2014. VII. 3, BC 14 MO- 030 (3 males, genitalia illustrated); Qualicum Beach, Nanaimo, 49.35664 ° N, 124.48334 ° W, M. Ôhara, 2016. VIII. 4, BC 16 MO- 032 (17 males, 6 females); Qualicum Beach, Nanaimo, 49.86327 ° N, 125.11438 ° W, M. Ôhara, 2016. VIII. 5, BC 16 MO- 033 (1 female); Campbell River, 50.00677 ° N, 125.23288 ° W, M. Ôhara, 2016. VIII. 7, BC 16 MO- 040 (7 males, 6 females). USA: Washington. Neptune Beach, Lummi Reservation, Ferndale, 48.79467 ° N, 122.71103 ° W, B. Oxborrow, 2016. X. 25, WA 16 AS- 015 (4 males); Derelict Conveyor, Ferndale, Whatcom Co., 48.855832 ° N, 122.72963 ° W, A. Suzumura, 2018. VIII. 26, WA 18 AS- 015 (3 males, 3 females). JAPAN: Hokkaido. “ Tachimachi-misaki / Hakodate, Hokkaido / Japan, 8 - IX- 1995 / M. Ôhara [under seaweed] ” (1 male: SEHU 0000027966); “ Tachimachi-misaki / Hakodate, Hokkaido / Japan, 8 - IX- 1995 / M. Ôhara [under seaweed] ” (1 male: SEHU 0000027860); “ Hokkaido: JAPAN / Aikage, Teuri-to, / Off Haboro / TE- 08 - MO- 007 / 44 ° 25 ’ 07 ” N, 141 ° 19 ’ 16 ” E / 15. VI. 2008, M. Ôhara / Under sea weed ” (2 males: SEHU 0000027838, SEHU 0000027839); “ Hokkaido: JAPAN / Tomisato, Okushiri-to / Off Setana / OK- 08 - MO- 015 / 42 ° 04 ’ 18 ” N, 139 ° 28 ’ 17 ” E / 12. VII. 2008, M. Ôhara / under sea weed ” (2 males: SEHU 0000027901, SEHU 0000027900); “ Tokachi: Hokkaido: Japan / Oshirabetsu, Hiroo / HK- 09 - MO- 007 / cobble beach / 42 ° 07 ’ 40 ” N, 143 ° 19 ’ 03 ” E / 5. VI. 2009, M. Ôhara / Under seaweed ” (1 male: SEHU 0000028026); “ Nemuro: Hokkaido: JAPAN / Shoji riv., Rausu, / 44 ° 07 ’ 09 ” N, 145 ° 15 ’ 12 ” E / 13 - IX- 2009, M. Ôhara, / H. Yamamoto and M. Furuta / under seaweeds (Laminaria) / [HK- 09 - MO 097 / CO] ” (1 male: SEHU 0000027994); Motoineppu, Oumu, Monbetsu, 44.624293 ° N, 142.931578 ° E, A. Suzumura leg., 2018. VI. 26, HK 18 AS- 027 (3 males). Honshu. “ Japan: Shimane / Izumo-shi Takicho Kumura / Tamura beach / 5. Oct. 2008 / T. Hayama leg. ” (1 male: SEHU 0000028111). Ryukyu Islands. “ Onna, Onnason / Okinawa-ken, Japan / 26 ° 29 ’ 34 ” N, 127 ° 50 ’ 34 ” E / [seashore], 25. vii. 2015 / Takuma Yoshida leg. ”	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	distribution	Distribution. Palearctic: Russian Federation (Far East), Japan, Korea; Nearctic: British Columbia, northern Washington (Fig. 4 A, C).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	discussion	Remarks. Cercyon dux is easily distinguished from other littoral Cercyon by its large size, lack of dorsal microsculpture, and presence of an oily, feltlike patch of setae covering the mentum in males. This is the first Nearctic record of this species, and it has so far only been collected from a few localities in the Strait of Georgia region of the Salish Sea (Fig. 4 C). Only individuals of the second, darker coloration have been found in North American populations. The absence of records of this distinctively large species in the region prior to 2014 suggests a recent introduction. One possibility is that it may have been directly introduced from Asia via debris generated by the 2011 Tohoku Earthquake Tsunami Disaster, though more physiological and phylogenetic studies are needed to better support or refute this hypothesis. Cercyon (Cercyon) fimbriatus Mannerheim 1852 (Figs. 1 E, F, 2 C, 4 B, 7 G – I, 9)	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	description	Redescription. Body length = 2.8 – 3.5 mm, width = 1.6 – 2.1 mm; body oval, convex though dorsoventrally compressed (Figs. 1 E – F, 9 A), body outline interrupted between pronotum and elytra; glabrous with dense punctation. Surface shiny on head and pronotum, elytra matte, color patterns (Fig. 1 E, F) as follows: 1) piceous with lateral margins and apex of elytra paler, fulvous; 2) head and disc of pronotum piceous, lateral margins of pronotum paler, fulvous, elytra yellow to light brown, opaque, often with dark crescentic spot on apical third, scutellum and elytral suture darkened. Ventrally piceous with white pubescence; femora fulvous to piceous; maxillary palpi and antennal club testaceous; scape, pedicel, and flagellum testaceous to fulvous. Head covered with punctures separated by about 2 X their diameter except a narrow space around epicranial sutures; clypeus truncate, anterior margin emarginate, with marginal stria (Fig. 9 B). Eyes separated by about 10 X their width dorsally. Mentum trapezoidal, convex, widened to apical 2 / 5 and narrowed anteriorly, anterior margin truncate, carinate, depressed behind; with sparse punctures separated by about 3 – 5 X their diameter, denser posteriorly; interspaces filled with dense, rugose microsculpture (length: width index = 0.44). Maxillary palpi about 0.6 X width of head, 2 nd palpomere swollen apically, about 2 X as long as wide, apical palpomere fusiform, slightly longer than penultimate. Male with adhesion disks on maxillae, their diameter a little over 1 / 3 width of mentum. Antenna about 0.70 X width of head; pedicel about 0.27 X as long as scape; club compact, about 2 X as long as wide. Pronotum widest at base, lateral margins evenly rounded; surface covered with dense punctures separated by a little more than their diameter; without microsculpture. Elytra with sides regularly curved, widest at about half length; with 9 deeply impressed striae, 1 st 2 curved towards each other, often seemingly joined at base (Fig. 9 D). Prosternum weakly tectiform, almost flat except for median carina, with well-defined grooves for reception of antennal club; pubescent, not reaching lateral margin. Mesoventral tablet variably shaped, fusiform, widest at about half length, acute anteriorly, rounded posteriorly (length: width index = 3.3 – 4.7) (Fig. 9 E, F); surface flat, shiny, densely punctate. Metaventrite with raised pentagonal plate, convex, projecting anteriorly between mesocoxae and almost contacting posterior margin of mesoventral plate; shiny, densely punctate, punctures separated by about their diameter; lateral portions densely pubescent, lacking punctures or femoral lines. Femora punctate, punctures separated by about 2 X their diameter; interspaces with dense granulate microsculpture. Tibiae with dense granulate microsculpture. Aedeagus as in Fig. 7 G – I; median lobe with apical 1 / 5, tapered to a truncate apex, bearing short setae; parameres apically rounded with a membranous protrusion on inner apical margin (genital ratio = 0.71). Specimens Examined. Paratype: “ Sitkha // MCZ- ENT 00007932 ” (1 sex undetermined). CANADA: British Columbia. Vancouver Isle: Alberthead Regional Park, Metchosin, 48.39583 ° N, 123.48833 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 005 (1 male); French Beach, Juan de Fuca, 48.39583 ° N, 123.94528 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 006 (1 sex undetermined); Otter Point, Sooke, 48.39667 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 007 (2 sex undetermined); Wickaninnish Beach, Ucluelet, 49.01611 ° N, 125.67417 ° W, M. Ôhara, 2014. VI. 29, BC 14 MO- 015 (9 sex undetermined); Half Moon Bay, Ucluelet, 48.94444 ° N, 125.61278 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 017 a (3 sex undetermined); Florencia Bay, Ucluelet, 49.98111 ° N, 125.61111 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 018 (4 sex undetermined); Long Beach, Ucluelet, 49.07028 ° N, 125.75583 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 019 (1 sex undetermined); Esowista, Long Beach, Ucluelet, 49.06861 ° N, 125.78417 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 020 (3 sex undetermined); Little Beach, Ucluelet, 48.93389 ° N, 125.54056 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 023 a (2 males); Terrace Beach, Ucluelet, 48.92861 ° N, 125.54722 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 024 (3 sex undetermined); Arbutus Grove Provincial Park, Nanoose Bay, 49.26194 ° N, 124.18889 ° W, M. Ôhara, 2014. VII. 3, BC 14 MO- 030 (6 sex undetermined); Qualicum Beach, Nanaimo, 49.35664 ° N, 124.48334 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 4, BC 16 MO- 032 (1 sex undetermined); Qualicum Beach, Nanaimo, 49.86327 ° N, 125.11438 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 5, BC 16 MO- 033 (2 male); Fort Rupert, near Port Hadley, 50.69515 ° N, 127.41035 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 6, BC 16 MO- 036 (1 sex undetermined); Sayward, 50.39783 ° N, 125.96224 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 7, BC 16 MO- 039 (1 sex undetermined); Perimeter Park, Metchosin, Colwood, 48.47530 ° N, 123.47365 ° W, M. Ôhara, 2016. VIII. 8, BC 16 MO- 044 (3 sex undetermined). USA: Alaska. Unalaska, Amaknak Island, 53.88491 ° N, 166.55671 ° W, M. Ôhara, 2015. VIII. 12 - 13, UN 15 MO- 019 (5 sex undetermined); Land End, Homer, Kenai Peninsula, 59.600849 ° N, 151.412078 ° W, M. Ôhara, 2015. VIII. 17, AL 15 MO- 022 (28 sex undetermined); Anchor Point, Homer, Kenai, Alaska, 59.77291 ° N, 151.87000 ° W, M. Ôhara, 2015. VIII. 18, AL 15 MO- 023 (21 sex undetermined); Nash Road, Seward Peninsula, 60.08330 ° N, 149.35199 ° W, M. Ôhara, 2015. VIII. 19, AL 15 MO- 029 (55 sex undetermined). Washington. Roosevelt Ocean Beach Access, Copalis Crossing, 47.17639 ° N, 124.19694 ° W, M. Ôhara, 2013. VI. 21, WA 13 MO- 039 (1 sex undetermined); Glenwood Creek, Snohomish Co., 47.959751 ° N, 122.248971 ° W, A. Suzumura, 2016. VI. 6, WA 16 AS- 006 (1 sex undetermined); Neptune Beach, Lummi Reservation, Ferndale, 48.79467 ° N, 122.71103 ° W, B. Oxborrow, 2016. X. 25, WA 16 AS- 015 (8 sex undetermined); Howarth Park, Snohomish Co., 47.96440 ° N, 122.24050 ° W, A. Suzumura, 2017. VI. 5, WA 17 AS- 001 (2 sex undetermined); Meadowdale, Snohomish Co., 47.85948 ° N, 122.33526 ° W, A. Suzumura, 2017. VI. 9, WA 17 AS- 004 (7 males); North of Battery Van Horne, Whidbey Island, 48.16159 ° N, 122.68286 ° W, A. Suzumura, 2017. VI. 24, WA 17 AS- 005 (2 males); Port Williams County Park, Sequim, Clallam Co., 48.097421 ° N, 123.046779 ° W, A. Suzumura, 2018. VIII. 14, WA 18 AS- 004 (1 sex undetermined); Dungeness Landing County Park, Sequim, Clallam Co., 48.151984 ° N, 123.143518 ° W, A. Suzumura, 2018. VIII. 21, WA 18 AS- 005 (1 sex undetermined); Cline Spit County Park, Sequim, Clallam Co., 48.151984 ° N, 123.152187 ° W, A. Suzumura, 2018. VIII. 21, WA 18 AS- 006 (1 sex undetermined); Port Angeles waterfront, Clallam Co., 48.119615 ° N, 123.428617 ° W, A. Suzumura, 2018. VIII. 21, WA 18 AS- 007 (1 sex undetermined); Chito Beach Resort, Sekiu, Clallam Co., 48.305656 ° N, 124.428559 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 009 (1 sex undetermined); unnamed beach, Sekiu, Clallam Co., 48.345279 ° N, 124.172070 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 010 (1 male); Hobuck Beach, Neah Bay, Makah Reservation, 48.336265 ° N, 124.663221 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 011 (1 sex undetermined); Clallem Bay Spit, Clallam Bay, Clallam Co., 48.255792 ° N, 124.26017 ° W, A. Suzumura, 2018. VIII. 23, WA 18 AS- 013 (1 sex undetermined); Washington Park Boat Landing, Anacortes, Skagit Co., 48.500156 ° N, 122.693686 ° W, A. Suzumura, 2018. VIII. 26, WA 18 AS- 016 (1 sex undetermined); Libbey Beach Park, Coupeville, Whidbey Island, 48.232156 ° N, 122.701029 ° W, A. Suzumura, 2018. VIII. 26, WA 18 AS- 017 (1 male). Oregon. OSAC _ 00000206873; OSAC _ 00000206879; OSAC _ 00000206882; OSAC _ 00000206894.	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	distribution	Distribution: Pacific Coast of North America, Alaska through Mexico (Fig. 4 B)	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	discussion	Remarks: The most common species of beachdwelling Cercyon in the region, C. fimbriatus can be easily distinguished by the deeply impressed, often connecting bases of the first and second striae (Fig. 9 D). Body size and coloration are highly variable within this species. Cercyon (Cercyon) luniger Mannerheim, 1853 (Figs. 1 G, H, 2 D, 4 B, 7 J – L, 10)	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	description	Redescription. Body length = 3.1 – 3.9 mm, width = 1.8 – 2.1 mm. Body oval, convex though dorsoventrally compressed (Figs. 1 G, H, 10 A); body outline continuous between pronotum and elytra. Surface shiny anteriorly, though becoming matte, rugose on posterior half of elytra. Head, pronotum, and scutellum piceous, lateral margins of pronotum often paler, testaceous; elytra fulvoustestaceous, often with crescentic oblique spot in apical third (Fig. 1 G, H). Ventrally piceous with pale pubescence, legs and maxillary palpi testaceous to fulvous. Head covered with dense punctures separated by a little more than their diameter except a narrow space around epicranial suture; interspaces with dense, granulate microsculpture except along median line and posterolaterally to epicranial sutures; clypeus anteriorly truncate with marginal stria, anterior corners rounded (Fig. 10 B). Eyes separated by about 9 X their width dorsally. Mentum trapezoidal to almost rectangular (length: width index = 0.52), anterior margin carinate, depressed behind; surface with uniform, dense granulate microsculpture and long setae around lateral and posterior margins. Maxillary palpi a little longer than half width of head; 2 nd palpomere swollen apically, a little over 2 X as long as wide; apical palpomere fusiform, slightly longer than penultimate. Male with adhesion discs on maxillae, diameter about 1 / 4 width of mentum (Fig. 10 C). Antenna about 0.90 X width of head; pedicel about 1 / 5 length of scape; club compact, about 2 X as long as wide. Pronotum widest at base, lateral margins evenly rounded; surface covered with dense punctures separated by a little more than their diameter; without microsculpture except a small area behind anterolateral corners (Fig. 10 D). Elytra with sides regularly curved; widest at about half length; with 10 relatively superficial striae, becoming less impressed posteriorly and laterally; 10 th stria almost completely unimpressed, only marked by dark pigmentation. Intervals flat with dense punctures separated by 1 – 2 X their diameter; interspaces with sparse rugose microsculpture and dense granulate microsculpture. Prosternum weakly tectiform, with a weak or incomplete carina medially; with grooves for reception of antennal club; pubescent though not reaching lateral margin. Mesoventral tablet extremely narrow, almost linear (length: width index> 10.0), surface flat, shiny, with fine punctures (Fig. 10 E, F). Metaventrite with raised pentagonal plate, convex, projecting anteriorly between mesocoxae and almost contacting posterior margin of mesoventral plate; shiny, sparsely punctate, punctures separated 2 – 5 X their diameter; lateral portions densely pubescent, lacking punctures or femoral lines (Fig 10 E). Femora with punctures separated by about 2 – 3 X their diameter, interspaces with dense to indistinct granulate microsculpture. Tibiae apically rounded, with dense granulate microsculpture. Aedaegus as in Fig. 7 J – L, median lobe roundly narrowed to apex; with short, indistinct setae; parameres extremely wide, apical 2 / 5 almost triangular, apical margin flat (genital ratio = 0.71). Specimens Examined. Lectotype: “ Kadjak // Holmberg // Cercyon / lunigerum / Mannerheim // Cercyon luniger / Mannh. / Smetana des 1974 / LECTOTYPE // Mus. Zool. H: fors / Spec. typ. No 2379 / Cercyon lu- / nigerum / Mannh. // Mus. Zool. Helsinki / Loan No. / CA 32 // Photographed / 2019 / Pekka Malinen // http: // id. luomus. fi // GAC. 28090 / UNITED STATES Alaska / Kodiak / 57.47 N, 152.48 W / Holmberg leg. ” (LUOMUS). Paralectotype: “ Type 7930 // C. lunigerum / Kadjak. Mann. // MCZ-ENT 00007930 ” (MCZ). CANADA: British Columbia, Vancouver Isle. Alberthead Regional Park, Metchosin, 48.39583 ° N, 123.48833 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 005 (1 sex undetermined); Otter Point, Sooke, 48.39667 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 007 (1 male); Whiffin Spit Beach, Sooke, 48.35694 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 27, BC 14 MO- 008 (1 male); Sombrio Beach, Juan de Fuca, 48.4981 ° N, 124.30000 ° W, M. Ôhara, 2014. VI. 27, BC 14 MO- 010 (2 males); Nanaimo, Nanaimo, 49.17583 ° N, 123.94165 ° W, M. Ôhara, 2014. VI. 28, BC 14 MO- 013 (1 sex undetermined); Little Beach, Ucluelet, 48.93389 ° N, 125.54056 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 023 a (1 male); Big Beach, Ucluelet, 48.93500 ° N, 125.55250 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 025 (6 males, 1 female); Connox Bay, Royston, 49.64917 ° N, 125.94417 ° W, M. Ôhara, 2014. VII. 2, BC 16 MO- 027 (1 sex undetermined); Sayward, 50.39783 ° N, 125.96224 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 7, BC 16 MO- 039 (1 sex undetermined). USA: Washington. “ Bowser, B. C. / VI. 8: - 55 / W. J. Brown // C. luniger / det. M. Hatch ” OSAC _ 000184564, OSAC _ 000184565; just North of Battery Van Horne, Whidbey Island, 48.16159 ° N, 122.68286 ° W, A. Suzumura, 2017. VI. 24, WA 17 AS- 005 (3 males, 1 female); Whisky Creek Beach, Port Angeles, Clallam Co., 48.15557 ° N, 123.780673 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 008 (13 sex undetermined); unnamed beach, Sekiu, Clallam Co., 48.345279 ° N, 124.172070 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 010 (4 sex undetermined).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	distribution	Distribution: Pacific Coast of North America, Alaska through Mexico (Fig. 4 B).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	discussion	Remarks: Cercyon luniger is similar to C. whuljensis and often found living with it (Smetana 1978) but differs in the shape of the male parameres, the presence of a small area of microsculpture on the apical angles of the pronotum, and paler elytral coloration. Due to the close external similarities, specimens of C. whuljensis in OSAC were previously identified by Hatch (OSAC _ 0000186121 – OSAC _ 0000186126) and described within C. luniger in Smetana (1988), but examination of the genitalia revealed that what had previously been considered interspecific variation in coloration and microsculpture, corresponds, in fact, to two different species (Suzumura 2019). The genitalia illustrated as belonging to C. spathifer in Smetana (1978) correspond to this species, whereas the genitalia illustrated as belonging to C. luniger in Smetana (1988) correspond to C. whuljensis. Cercyon (Cercyon) setulosus Sharp, 1884 (Figs. 1 I, J, 2 E, 4 A, 7 M – O, 12, 13)	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	description	Redescription. Body length = 2.0 – 2.8 mm, width = 1.0 – 1.4 mm; body oblong, convex though dorsoventrally compressed (Figs. 1 I, J, 12 A); surface matte, predominately covered with microsculpture. Body outline interrupted between pronotum and elytra, piceous, lateral margins of pronotum and elytra, apical portion of elytra, and elytral suture often paler (Fig. 1 I, J). Ventrally piceous with pale pubescence, legs and maxillary palpi testaceous. Eyes separated by about 10 X their width. Head covered with fine punctures, separated by a little more than their diameter except around epicranial sutures, interspace with dense granulate microsculpture; clypeus anteriorly truncate with marginal striae, anterior corners rounded (Fig. 12 B). Mentum trapezoidal, anterior margin emarginate and carinate, sparsely punctate with interspaces filled with microsculpture consisting of short, horizontal wrinkles (length: width index = 2.44). Maxillary palpi a little less than 0.5 X width of head, 2 nd palpomere swollen apically, apical palpomere fusiform and a little longer than penultimate. Male with small, indistinct adhesion disks on maxillae, their diameter about 1 / 4 width of mentum (Fig. 12 C). Antenna about 0.70 X width of head, pedicel about ¼ length of scape, club compact, about 2 X as long as wide. Pronotum widest at base, about 2 X as wide as long, lateral margins evenly rounded, surface covered with dense punctures separated by a little more than their diameter, interspaces with granulate microsculpture (Fig. 12 D), densest laterally and reduced towards center. Elytra with sides regularly curved, widest at about middle, with 10 deeply impressed striae, sometimes transversely indented parallel to margin; intervals flat, with fine punctures separated by 2 – 3 X their diameter, interspaces with fine microrugae and sparse, indistinct, decumbent pubescence laterally from 6 th stria and in posterior third (Fig. 12 G). Prosternum tectiform, carinate medially, with well-defined grooves for reception of antennal club, pubescent. Mesoventral plate fusiform though variably shaped, widest at about middle, acute and often constricted anteriorly (length: width index = 2.0 – 3.0) (Fig. 12 E, F), surface flat, shiny, sparsely punctate. Metaventrite with raised pentagonal plate, convex, shiny and irregularly punctate, projecting anteriorly between mesocoxae and contacting mesoventral tablet at a single point, lateral portions densely pubescent, lacking punctures or femoral lines (Fig. 12 E). Femora with punctures separated by about 3 X their diameter, interspaces with dense granulate microsculpture. Tibiae with indistinct granulate microsculpture. Aedaegus as in Fig. 7 M – O; median lobe evenly tapered to a point with long, sparse setae on apical fourth; parameres apically narrowed and diagonally truncate at tips (genital ratio = 0.92). Specimens Examined. Paratypes: “ Bowser, B. C. / VI. 8 - 55 / W. J. Brown // PARATYPE / Cercyon (s. str) / tolfino Hatch / 1960 // OSAC _ 0000063017 - 0000063021 ” (5 sex undetermined). CANADA: British Columbia, Vancouver Isle.: Alberthead Regional Park, Metchosin, 48.39583 ° N, 123.48833 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 005 (1 sex undetermined); French Beach, Juan de Fuca, 48.39583 ° N, 123.94528 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 006 (3 sex undetermined); Otter Point, Sooke, 48.39667 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 26, BC 14 MO- 007 (2 males, 2 females); Whiffin Spit Beach, Sooke, 48.35694 ° N, 123.86694 ° W, M. Ôhara, 2014. VI. 27, BC 14 MO- 008 (3 males); Sombrio Beach, Juan de Fuca, 48.4981 ° N, 124.30000 ° W, M. Ôhara, 2014. VI. 27, BC 14 MO- 010 (9 sex undetermined); Brown’ s Beach, Ucluelet, 49.93750 ° N, 125.55778 ° W, M. Ôhara, 2014. VI. 29, BC 14 MO- 016 a (2 sex undetermined); Florencia Bay, Ucluelet, 49.98111 ° N, 125.61111 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 018 (1 sex undetermined); Chesterman Beach, Tolfino, 49.12250 ° N, 125.89694 ° W, M. Ôhara, 2014. VI. 30, BC 14 MO- 022 (1 sex undetermined); Little Beach, Ucluelet, 48.93389 ° N, 125.54056 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 023 a (1 male, 13 sex undetermined); Terrace Beach, Ucluelet, 48.92861 ° N, 125.54722 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 024 (20 sex undetermined); Big Beach, Ucluelet, 48.93500 ° N, 125.55250 ° W, M. Ôhara, 2014. VII. 1, BC 14 MO- 025 (2 sex undetermined); Connox Bay, Royston, 49.64917 ° N, 125.94417 ° W, M. Ôhara, 2014. VII. 2, BC 14 MO- 027 (7 sex undetermined); Arbutus Grove Provincial Park, Nanoose Bay, 49.26194 ° N, 124.18889 ° W, M. Ôhara, 2014. VII. 3, BC 14 MO- 030 (4 males); Transfer Beach Park, Ladysmith, 49.26194 ° N, 124.18889 ° W, M. Ôhara, 2014. VII. 3, BC 14 MO- 031 (32 sex undetermined); Qualicum Beach, Nanaimo, 49.35664 ° N, 124.48334 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 4, BC 16 MO- 032 (8 males, 2 female, 69 sex undetermined); Fort Rupert, near Port Hadley, 50.69515 ° N, 127.41035 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 6, BC 16 MO- 036 (7 males); Sayward, 50.39783 ° N, 125.96224 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 7, BC 16 MO- 039 (1 sex undetermined); Campbell River, 50.00677 ° N, 125.23288 ° W, M. Ôhara, 2016. VIII. 7, BC 16 MO- 040 (7 males); Otter Point, Muir Creek Beach, Sooke, 48.37970 ° N, 123.86755 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 8, BC 16 MO- 042 (5 males); Whiffin Spit, Sooke, 48.37970 ° N, 123.86755 ° W, M. Ôhara and N. Kobayashi, 2016. VIII. 8, BC 16 MO- 043 (2 sex undetermined); “ Bowser, BC / VI. 8 - 55 / W. J. Brown ”. USA: Alaska. Whitter, Kenai Peninsula, 60.78064 ° N, 148.71776 ° W, M. Ôhara, 2015. VIII. 17, AL 15 MO- 021 (7 sex undetermined); Land End, Homer, Kenai Peninsula, 59.600849 ° N, 151.412078 ° W, M. Ôhara, 2015. VIII. 17, AL 15 MO- 022 (19 sex undetermined); Lowel Point, Seward, Kenai Peninsula, 60.07127 ° N, 149.43613 ° W, M. Ôhara, 2015. VIII. 19, AL 15 MO- 028 (4 sex undetermined). Washington. Snohomish Co: Glenwood Creek, Snohomish Co., 47.959751 ° N, 122.248971 ° W, A. Suzumura, 2016. VI. 6, WA 16 AS- 006 (3 males, 2 females, 1 sex undetermined); Chito Beach Resort, Sekiu, Clallam Co., 48.305656 ° N, 124.428559 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 009 (1 sex undetermined); unnamed beach, Sekiu, Clallam Co., 48.345279 ° N, 124.172070 ° W, A. Suzumura, 2018. VIII. 22, WA 18 AS- 010 (1 sex undetermined); Derelict Conveyor, Ferndale, Whatcom Co., 48.855832 ° N, 122.729630 ° W, A. Suzumura, 2018. VIII. 26, WA 18 AS- 015 (1 sex undetermined); Libbey Beach Park, Coupeville, Whidbey Island, 48.232156 ° N, 122.701029 ° W, A. Suzumura, 2018. VIII. 26, WA 18 AS- 017 (1 sex undetermined). JAPAN: Hokkaido: “ Daikoku-jima: Akkeshi: Hokkaido / 42 ° 57 ’ 39 ” N, 144 ° 52 ’ 11 ” E / 12. VII. 2005, M. Ôhara ”, DA 05 MO- 005 (2 males: SEHU 0000029423, SEHU 0000029424); “ Hokkaido: Japan / Yagishiri-to / Off Haboro / 44 ° 26 ’ 02 ” N 141 ° 25 ’ 41 ” E / 16. VI. 2008, M. Ôhara / Under sea weed ” YA 08 MO- 010 (1 male: SEHU 0000028193); “ Oshima: Hokkaido: Japan / Osatsube, Minami-kayabe / 41 ° 53 ’ 37 ” N, 141 ° 00 ’ 42 ” E / 15. VII. 2009, M. Ôhara / under seaweeds (Laminaria sp.) ” HK 09 MO- 041 / SI (1 male: SEHU 0000029596); “ Soya: Hokkaido: JAPAN / Higashiura, Wakkanai / 45 ° 25 ’ 09 ” N 142 ° 02 ’ 02 ” E / 23. VII. 2008, M. Ôhara / under seaweeds (Laminaria) and eel grass (Zostera) ” HK 09 MO- 051 / SI (1 male: SEHU 0000029538; 2 females: SEHU 0000029539, SEHU 0000029540); Nosappu, Nemuro, 43.3855492 ° N, 145.81350176 ° E, A. Suzumura, 2018. VI. 17, HK 18 AS- 017 (2 males, 3 females).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	distribution	Distribution. Palearctic: Kuril Islands, Japan, Russia Federation; Nearctic: Alaska through Washington (Fig. 4 A).	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
03FD136EB94DA928FF0AEDB7FE5AFD75.taxon	discussion	Remarks. Cercyon setulosus is a very small, flat species characterized by the presence of dense microsculpture on most of the dorsal surface. Cercyon tolfino was placed in junior synonymy with C. setulosus by Shatrovskiy (1992), but the revision was either overlooked or not accepted as the two names have continued to be used. We are basing our understanding of this species on specimens examined by Shatrovskiy. This confirmed synonymy gives it a trans-Pacific distribution, ranging along the coastlines of the Northern Pacific Rim from northern Japan to Washington State.	en	Suzumura, Alyssa Lee, Kobayashi, Norio, Ôhara, Masahiro (2019): Revision of the Beach-Dwelling Species of Cercyon Leach (Coleoptera: Hydrophilidae) of the West Coast of North America. The Coleopterists Bulletin 73 (3): 473-493, DOI: 10.1649/0010-065X-73.3.473, URL: http://dx.doi.org/10.1649/0010-065x-73.3.473
