taxonID	type	description	language	source
2C7E87EDF16E263C69EC288CFCD85954.taxon	diagnosis	Diagnosis: Callioplanidae with nuchal tentacles. Cerebral and tentacular eye clusters present. Pharynx anteriorly located. Male copulatory apparatus with seminal vesicle and elongated rod-like unarmed penis. Female apparatus directed backwards running along the male tract dorsally. Lang’s vesicle present.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16E263C69EC288CFCD85954.taxon	type_taxon	Type species: Callioplana marginata Stimpson, 1857.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16E263E69EC2EC5FD475967.taxon	description	(Fig. 4)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16E263E69EC2EC5FD475967.taxon	materials_examined	Material examined: Five specimens, one sagittally sectioned. AM W. 50270 (12 slides); AM W. 50271, W. 50272, W. 50274, W. 50275 (wet material). Specimens were collected intertidally at low tide from the following sites in Australia, New South Wales: Norah Head rock platform, 33 ° 16 ’ 43.14 ” S, 151 ° 34 ’ 12.85 ” E and Toowoon Bay, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 15 th & 16 th, 2018. Additional material from Australia, New South Wales, Long Reef from the collections of the Australian Museum: AM W. 3695, W. 3696.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16E263E69EC2EC5FD475967.taxon	discussion	Remarks: The studied specimens agree with the previous descriptions and anatomical reconstructions of C. marginata from Japan by Yeri & Kaburaki (1918) and Kato (1944). Externally, the specimens present orangecoloured conical nuchal tentacles that are colourless at the base, and a mouth situated in the centre of the body (Fig. 4 A). The male copulatory system presents a non-muscular seminal vesicle and an oval-shaped prostatic vesicle, as well as separated ejaculatory and prostatic ducts that run parallel to each other along the elongated penis papilla. The long female system is positioned dorsal to the male copulatory system and is provided with a paired Lang’s vesicle consisting of elongated saccular bodies (Figs 4 B, C). Hyman (1959) notes that the description of the colouration of C. marginata varies in the following configurations: almost black with a red margin (Schmarda, 1859); almost black with a narrow light margin (Haswell 1907); velvety black with a tawny brown band and colourless margin (Kato 1944); and sepia brown with a deeper brown on the inner side and a white margin subtended by an orange brown band (Hyman 1959, based on the description provided by Elizabeth Pope). Hyman also remarks that the general pattern is a dark dorsal surface with a contrasting tawny brown to orange margin that is bordered thinly by white. In the specimens found in this study, the colouration of the dorsal surface presented a slight variation among different individuals (Fig. 4 A, bottom row). Although the background colour was black, in some specimens the area between the pharynx and the body margin appeared less pigmented, with a cloud of very small black dots. In specimens where the pigmentation appeared completely black, this paler section could also be noticed under different lighting (higher contrast / light intensity) (Fig. 4 A, top row). Furthermore, the dorsal surface could appear as brownish sepia, and the marginal band as orange, yellowish or tawny brown, depending on contrast and lighting. Body margin may also appear ruffled depending on the size of the animal (Fig. 4 A, top row). Molecular remarks: The sequenced specimen of Callioplana marginata appeared in a common clade with the specimen from Australia sequenced by Litvaitis et al. (2019) and from Japan by Oya & Kajihara (2020) with high support (100 / 1.00) and short branch lengths.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16E263E69EC2EC5FD475967.taxon	distribution	Distribution: Japan: Ousima (Stimpson 1857, type locality), Kanayama, Seto in Shirahama-cho (Kato 1938), Amami Islands, Misaki, Sunosaki, Susaki near Simoda (Kato 1944); Sri Lanka: Trincomalee (Kato 1944); Australia: NSW, Port Jackson (Haswell 1907), Long Reef near Collaroy (Hyman 1959). Even though this species presents a wide geographical distribution, both morphological and molecular results indicated that individuals reported from Japan and Australia are the same species. Stummer-Traunfels (1933), after reinvestigating the material of Schmarda (1859), synonymised Stylochus oxyceraeus from Trincomalee (Sri Lanka) and Diplosolenia Johnstoni (Australia) to C. marginata. Considering that accounts of the sexual anatomy were given for all of these specimens, which belong to the same species, the presence of C. marginata in Sri Lanka should be valid as well. Genus Neostylochus Yeri & Kaburaki, 1920	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263E69EC2EF9FC4E5A6A.taxon	diagnosis	Diagnosis (after Faubel 1983): Callioplanidae with tentacular, cerebral and marginal eye-spots. Tentacles reduced to knobs may be present. Pharynx extends anterior to the centre. Male copulatory apparatus with seminal vesicle and penis armed with an elongated tubular stylet. Lang’s vesicle present.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263E69EC2EF9FC4E5A6A.taxon	type_taxon	Type species: Neostylochus fulvopunctatus Yeri & Kaburaki, 1920.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	description	(Fig. 5)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	materials_examined	Material examined: One specimen sagittally sectioned. Holotype: AM W. 50265 (14 slides). Type locality: Australia, New South Wales, Catherine Hill Bay, Middle Camp Beach, found in Ecklonia radiata holdfasts washed up onto the rock platform at the north end of the beach, 33 ° 8 ’ 45.93 ” S, 151 ° 38 ’ 18.00 ” E. Coll. Alex Hegedus and Jorge Rodriguez, May 6 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	etymology	Etymology: The name of the species refers to the anchor-shaped seminal vesicle present in the male copulatory system.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	description	Description: Body oval broader anteriorly and with rounded ends. Fixed specimen 0.8 cm long. Dorsal surface slightly transparent with pale brown colour (Fig. 5 A, C). Tentacular and cerebral eyes lie scattered in frontal region. Marginal eyes present in a band along the anterior margin (Fig. 5 D). Ruffled pharynx located in middle part of the body, with oral pore opening posterior to its centre (Fig. 5 A). Male and female gonopores located very close together in the posterior part of the body. Male copulatory apparatus consists of a seminal vesicle, free prostatic vesicle and a penis papilla armed with a long and tubular stylet, directed backwards (Fig. 5 E). Vasa deferentia run ventrally along both sides of the pharyngeal cavity (Fig. 5 A), joining distally the seminal vesicle. Seminal vesicle anchor-shaped. Prostatic vesicle oval-shaped, covered with a thick muscular layer and lined with thin smooth glandular epithelium (Fig. 5 F – I). Ejaculatory duct joins prostatic duct at base of the penis. Male atrium elongated, housing a long penis stylet (Fig. 5 G – I). Female system located close behind male apparatus. Vagina runs dorsally, makes a loop towards the male system, receives the oviducts and continues into the Lang’s vesicle (Fig. 5 G – I). Lang’s vesicle thick and provided with vacuolar internal lining (Fig. 5 B, F – I).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	discussion	Remarks: The new species belongs to the genus Neostylochus due to the presence of tentacular and cerebral eyes scattered in the frontal region with marginal eyes in the anterior margin, male copulatory system with seminal vesicle and elongated tubular stylet and presence of a Lang’s vesicle. There are currently three known species for the genus Neostylochus: N. caraibica (Palombi, 1923) from the Caribbean Sea, N. fulvopunctatus (Yeri & Kaburaki, 1920) from Misaki (Japan), and N. pacificus (Bock, 1923) from Juan Archipelago (Chile). The most conspicuous characteristics of N. ancorus sp. nov. are the anchor-shaped seminal vesicle and vacuolar Lang’s vesicle. Neostylochus fulvopunctatus presents brown spots scattered in its dorsal region that differ from the colouration pattern of N. ancorus sp. nov. Both N. pacificus and N. caraibica were described based on fixed material and therefore no account of their colour is available. Neostylochus pacificus lacks marginal eyes in the anterior region and presents eyes distributed over the top of the pharyngeal region, which are lacking in N. ancorus sp. nov. Neostylochus fulvopunctatus presents larger tentacular eye spots in respect to the cerebral ones while both are the same size in N. ancorus sp. nov. Neostylochus pacificus presents tentacles reduced to small knobs, which are not present in N. ancorus sp. nov., N. fulvopunctatus and N. caraibica. Neostylochus ancorus sp. nov. differs from the other species by the presence of an anchor-shaped seminal vesicle, in contrast with the oval-shaped seminal vesicle present in the other species. Furthermore, the Lang’s vesicle of N. ancorus sp. nov. is larger and filled with vacuolar elements which are not present in any of the currently described species in this genus. Molecular remarks: Neostylochus ancorus sp. nov. was positioned inside the Stylochoidea superfamily in the ML analysis with BS support <70 (61) while it appeared within the Leptoplanoidea superfamily with high support (1.00) in the Bayesian analysis as sister taxa for Echinoplana celerrima Haswell, 1907. The genus Neostylochus is currently located within the Callioplanidae family yet Neostylochus ancorus sp. nov. did not appear together with Callioplana marginata, the type of the family and genus. It is clear that the position of Neostylochus within Callioplanidae is incorrect and a revision of the family is needed, yet with the currently available data its position cannot be determined.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16C263869EC2D98FD385A32.taxon	distribution	Distribution: Known only from type locality.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16A263B69EC2D20FB8D5CE6.taxon	diagnosis	Diagnosis (after Faubel 1983, emended): Latocestidae with cerebro-frontal eyes scattered in a fan-like pattern. Ruffled pharynx located in the most posterior part of the body. Separate gonopores. Male copulatory apparatus without seminal vesicle but spermiducal bulbs present; penis papilla-like and unarmed. Prostatic vesicle with thick glandular layer consisting of a web of follicles. Female apparatus simple with either Lang’s vesicle or without Lang’s vesicle and ductus vaginalis.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16A263B69EC2D20FB8D5CE6.taxon	type_taxon	Type species: Eulatocestus pacificus (Laidlaw, 1903).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF16A263B69EC2D20FB8D5CE6.taxon	discussion	Remarks: The original description of the genus by Faubel (1983) indicates the presence of a Lang’s vesicle, however, the diagnosis is emended to include the possible presence of a ductus vaginalis.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	description	(Fig. 6)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	materials_examined	Material examined: One specimen sagittally sectioned. Holotype: AM W. 50261 (10 slides). Type locality: Australia, New South Wales, Catherine Hill Bay, Middle Camp Beach, found in Ecklonia radiata holdfasts washed up onto the rock platform at the north end of the beach, 33 ° 8 ’ 45.93 ” S, 151 ° 38 ’ 18.00 ” E. Coll. Alex Hegedus and Jorge Rodriguez, August 6 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	etymology	Etymology: The specific epithet refers to the geographical location of its discovery, Australia, following the naming convention of the other species in the genus.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	description	Description: Body slender and elongated with rounded ends. Fixed specimen 1.0 cm long. Dorsal surface with reddish brown colour. Tentacles absent. Cerebro-frontal eyes scattered in a fan-like pattern from brain to anterior margin; marginal eyes present in a single band alongside anterior margin (Fig. 6 A). Ruffled pharynx located in the most posterior part of the body, with oral pore opening in its posterior region (Fig. 6 B). Male and female gonopores located close together in most posterior part of the body. Male copulatory apparatus consists of a free prostatic vesicle and a small penis papilla, directed backwards (Fig. 6 C). Vasa deferentia run ventrally along both sides of posterior body region (Fig. 6 B), swelling into spermiducal vesicles before joining ejaculatory duct at base of penis papilla (Fig. 6 F). No seminal vesicle. Prostatic vesicle oval-shaped, covered in a well-developed muscle layer and provided with a web-like glandular epithelium (Fig. 6 E). Male atrium small, housing a short, unarmed penis papilla (Fig. 6 F). Female system located directly behind male apparatus. Vagina runs dorsally, makes a small loop towards the male system, receives oviducts and loops back towards the female atrium through a ductus vaginalis. Lang’s vesicle lacking (Fig. 6 D, F).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	discussion	Remarks: The new species belongs to the genus Eulatocestus due to the presence of cerebro-frontal eyes scattered in a fan-like pattern, ruffled pharynx located in the most posterior part of the body, male copulatory system without seminal vesicle and with spermiducal bulbs, and prostatic vesicle with thick glandular layers consisting of a web of follicles. There are currently three known species of Eulatocestus: E. caribbeanus (Prudhoe, 1944) from the Cayman Islands, E. galapagensis (Hyman, 1953 a) from the Galapagos Islands (Ecuador), and E. pacificus (Laidlaw, 1903 a) from the Rotuma (Fiji) and Palau Islands. Descriptions of these species were based on fixed material and therefore their colouration is unknown. The most conspicuous difference of Eulatocestus australis sp. nov. to these other described species is the lack of a Lang’s vesicle with presence of a ductus vaginalis. The type species of the genus Eulatocestus is E. pacificus, described from two immature specimens collected in Rotuma (Rotuma Islands, Fiji) and therefore lacking details of the reproductive system which are important generic characters. These specimens were first described as a new species, Latocestus pacificus, by Laidlaw in 1903 and at that time only one other species had been described in the genus Latocestus, L. atlanticus Plehn 1896, which looked different externally from these specimens. Later, Faubel (1983) created the genus Eulatocestus in 1983 for Latocestidae species with a thick web-like glandular epithelium in their prostatic vesicle, and selected Latocestus pacificus Laidlaw, 1903, as the type species with the new combination Eulatocestus pacificus (Laidlaw, 1903). However, the internal anatomy of E. pacificus was never described and therefore its position in the genus Eulatocestus is dubious. Furthermore, its classification as the type species of the genus should be considered and may need to be changed in the future. Molecular remarks: Eulatocestus australis sp. nov. appeared as sister taxa of Latocestus sp. with high support (99 / 0.91) in the Latocestidae family clade. As stated above, the genus Eulatocestus was created for Latocestidae species with a prostatic vesicle lined with a web-like glandular epithelium, a character present in this new species. Some morphological traits proposed by Faubel (1983) used to separate genera and families in the Order Polycladida, such as the nature of the internal epithelium and location of the prostatic vesicle, may not have such relevant phylogenetic value due to topology of our molecular phylogeny. Nevertheless, we propose to establish this newly described species in the genus Eulatocestus until more molecular data from species of Latocestidae is available.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	distribution	Distribution: Known only from type locality. Genus Leptostylochus Bock, 1925 b	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	diagnosis	Diagnosis (after Faubel 1983): Stylochidae with or without tentacles. Tentacular, cerebral, marginal, and often frontally strewn eye-spots present. Male copulatory apparatus with papilla-like unarmed penis and predominantly with spermiducal bulbs. Female apparatus with well-developed Lang’s vesicle.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF169263569EC2A14FCD75E43.taxon	type_taxon	Type species: Leptostylochus elongatus Bock, 1925 b.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC2E9EFCB45B65.taxon	diagnosis	Diagnosis (after Faubel 1983): Idioplanidae with tentacles; tentacular, cerebral and marginal eye-spots present. Male copulatory apparatus with seminal vesicle and papillate unarmed penis; vasa deferentia immediately unite before entering the seminal vesicle. Female apparatus extending dorsally along the male complex from an anterior position of the male apparatus. Lang’s vesicle anchor-shaped.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC2E9EFCB45B65.taxon	type_taxon	Type species: Idioplana australiensis Woodworth, 1898.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC29F3FAE55971.taxon	description	(Fig. 7)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC29F3FAE55971.taxon	materials_examined	Material examined: Three specimens, all sagittally sectioned. AM W. 50288 (6 slides), W. 51321 (2 slides), W. 51322 (2 slides). Specimens were found intertidally at low tide under small rocks from Australia, New South Wales at the following sites: north east side of Pulbah Island, Lake Macquarie, 33 ° 5 ’ 30.19 ” S, 151 ° 35 ’ 27.65 ” E. Coll. Jorge Rodriguez, May 18 th, 2018 and Boat Harbour, Gerroa, 34 ° 45 ’ 02.0 ” S, 150 ° 49 ’ 56.5 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 7 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC29F3FAE55971.taxon	discussion	Remarks: The studied specimens agreed with the ones described by Beveridge (2017) in both morphology and habitat. Externally, Leptostylochus victoriensis Beveridge, 2017 possesses an olive grey dorsal colouration with a pink coloured area around the genitals, cerebral eyes in two elongated clusters above the brain and a band of marginal eyes around the anterior margin of the body (Fig. 7 A). Internally, L. victoriensis is characterised by the presence of a free prostatic vesicle with ridged glandular epithelium, lack of seminal vesicle, presence of a long penis papilla housed in a tall male atrium and a female system with Lang’s vesicle (Fig. 7 B, C). Molecular remarks: Leptostylochus victoriensis appeared as sister taxon of Leptostylochus cf gracilis with high support (100 / 1.00) and nested within Stylochoidea.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF167263569EC29F3FAE55971.taxon	distribution	Distribution: Australia, Victoria, Separation Creek (Beveridge 2017, type locality). These new findings represent an extension on the geographical distribution range of this species for southeastern Australia.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2BC9FE8A58DF.taxon	description	(Fig. 8)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2BC9FE8A58DF.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 50276 (6 slides). A specimen was collected from Australia, New South Wales, Toowoon Bay, rocky headland adjacent to SLSC, found under rocks at low tide, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 16 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2BC9FE8A58DF.taxon	discussion	Remarks: The studied specimen agreed with the original species description in 1898 from Hope Islands (Great Barrier Reef, Australia). Externally, Idioplana australiensis is characterised by possessing a circular body shape, a pair of nuchal tentacles, marginal eyes in a band along the anterior body margin and a brownish orange colouration (Fig. 8 A, B). Internally, I. australiensis presents a free prostatic vesicle with ridged glandular epithelium, an ovalshaped seminal vesicle, a very short penis papilla, and a female system that extends dorsally over the male copulatory system provided with an anchor-shaped Lang’s vesicle (Fig. 8 C, D). Woodworth describes the general colour as bluish to yellowish or reddish, where the former can be attributed to the colouration of the intestine when seen through the dermis and the latter being the pigmentation of the dorsal surface (Fig. 8 A). Some small differences with the original specimen are the body form, described as slug-like while the present specimen had a more rounded shape, and the distance between the gonopores, originally described as more closely together than in the currently studied specimen which can be attributed to the preservation process. Molecular remarks: Idioplana australiensis appeared in a common clade with Idioplana atlantica Bock, 1913 and another specimen of I. australiensis from Phillip Island (Victoria, Australia), both sequenced by Litvaitis et al. (2019), with high support (100 / 1.00). The specimen described in this study, however, appeared more closely related to I. atlantica from Bocas del Toro (Panama) than the other specimen of I. australiensis, also with high support (97 / 0.91). This difference is most likely due to a mislabelling of the name of the sequences, where the sequence of I. atlantica would be that of I. australiensis and vice versa. Since no morphological data was provided for these species, another possibility for this difference could be the absence of additional molecular data, as only 28 S sequences are available on the GenBank database for these species.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2BC9FE8A58DF.taxon	distribution	Distribution: Australia, Great Barrier Reef, Hope Islands (Woodworth 1898, type locality). New record: Australia, New South Wales, Toowoon Bay. This record represents a major range extension of this species distribution.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2E4FFCE05B2C.taxon	diagnosis	Diagnosis (after Faubel 1983): Planoceridae with nuchal tentacles, tentacular and cerebral eye-spots. Male genital apparatus with true seminal vesicle and cirrus, lined with small chitinous spines, often with one to several large spines or hooks at the transition from the cirrus sac to the male atrium. Cirrus and prostatic vesicle enclosed in a large and highly muscularised cirrus bulb. The cirrus bulb involves cirrus vesicles. Female complex with very muscularised vagina bulbosa sometimes provided with spines, Lang’s vesicle reduced to a small sac or a long thread-like duct.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF165263769EC2E4FFCE05B2C.taxon	type_taxon	Type species: Planocera pellucida (Mertens, 1833).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	description	(Fig. 9)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 51340 (13 slides). Specimen was collected from Australia, Victoria, San Remo, found under rocks, 38 ° 31 ’ 11.9 ” S, 145 ° 22 ’ 02.2 ” E. Coll. Audrey Falconer, July 14 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	discussion	Remarks: The San Remo specimen agreed with the original species description by Prudhoe in 1982. Externally, Planocera edmondsi Prudhoe, 1982 possesses a rounded body, a pair of nuchal tentacles and a reddish brown dorsal colouration (Fig. 9 A). Internally, P. edmondsi is characterised by the presence of a free prostatic vesicle with tall and folded glandular epithelium, an oval-shaped seminal vesicle and a cirrus lined with spines and five teeth in its distal end, and a female system provided with a large and muscular external vagina and a short and tubular Lang’s vesicle (Fig. 9 B, C). Molecular remarks: Planocera edmondsi appeared in the Planocera clade together with P. pellucida (Mertens, 1833), P. reticulata (Stimpson, 1855) and P. multitentaculata Kato, 1944 with high support (99 / 1.00). The Planocera clade also appeared as the closest relative to the Paraplanocera clade with high support (99 / 1.00) in the Planoceridae family.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	distribution	Distribution: Australia: South Australia, St. Vincent Gulf, Port Noarlunga (Prudhoe 1982, type locality), Tasmania, Bass Strait, Deal Island, Little Squally Cove (Prudhoe 1982). New record: Australia, Victoria, San Remo. Genus Paraplanocera Laidlaw, 1903 Paraplanocera Laidlaw, 1903: 4 – 7.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	diagnosis	Diagnosis (after Faubel 1983): Planoceridae with oval or circular body. Robust and conspicuous nuchal tentacles present, without marginal eyes and with cerebral and tentacular eyes. Pharynx located in the central region of the body. Gonopores separate. Male reproductive system lacks a seminal vesicle, with a prostatic vesicle, spermiducal vesicle and cirrus sac with spines and conspicuous teeth. Female reproductive system with bursa copulatrix, vagina with scalloped epithelium and Lang ìs vesicle.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263169EC2BC9FC995902.taxon	type_taxon	Type species: Paraplanocera oligoglena (Schmarda, 1859).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263269EC2E3DFCA95CE5.taxon	description	(Fig. 10)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263269EC2E3DFCA95CE5.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 50277 (16 slides). A specimen was collected from Australia, New South Wales, Toowoon Bay, rocky headland adjacent to SLSC, found under rocks, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 16 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263269EC2E3DFCA95CE5.taxon	discussion	Remarks: The Toowoon Bay specimen agreed with the original species description by Meyer in 1922. Externally, Paraplanocera marginata Meyer, 1922 possesses a rounded body, a pair of nuchal tentacles and an orange yellow dorsal surface with scattered small white dots and a black marginal band with intermittent white streaks (Fig. 9 A). Internally, the male copulatory system of P. marginata is characterised by the presence of a free prostatic vesicle provided with tubularly chambered glandular epithelium in its proximal region, two oval-shaped seminal vesicles, a cirrus lined with spines that grow larger distally, and the presence of an accessory prostatic vesicle at the distal end of the cirrus bulb. The female system is provided with a bursa copulatrix, cement glands grouped in two pockets, and a long Lang’s vesicle (Fig. 9 B, C). Meyer (1922) described the marginal band of P. marginata as purple, while the one in the present specimen appeared black. Prudhoe (1989) notes that an individual of P. marginata from Australia was seen bearing a narrow submarginal black band, which matches that of the studied specimen. Molecular remarks: Paraplanocera marginata Meyer, 1922 appeared together with another specimen from Hawaii (USA) sequenced by Litvaitis et al. (2019) with high support (100 / 1.00). The Paraplanocera clade also appeared as the closest relative to the Planocera clade with high support (99 / 1.00) in the Planoceridae family.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF163263269EC2E3DFCA95CE5.taxon	distribution	Distribution: Red Sea (Meyer 1922, type locality); Kenya, Africa and the Persian Gulf (Prudhoe 1945); USA, Hawaii (Litvaitis et al. 2019). New record: Toowoon Bay, New South Wales (Australia).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160263269EC2A20FD105F5C.taxon	diagnosis	Diagnosis: Gnesiocerotidae with oval body. With small tentacles, without marginal eyes but with cerebral and tentacular eyes inside the tentacles. Pharynx anterior to the middle part of the body. Gonopores separate. Male reproductive system enclosed in a muscular bulb consisting of a seminal vesicle, interpolated prostatic vesicle lined with ridged glandular epithelium and a parabolic dish-like penis stylet. Male atrium provided with a glandulomuscular fold. Female reproductive system dorsal to the male apparatus, with thickened external vagina and without Lang’s vesicle.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160263269EC2A20FD105F5C.taxon	etymology	Etymology: The generic name refers to the parabolic dish-like shape of the penis stylet present in the male copulatory system.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160263269EC2A20FD105F5C.taxon	type_taxon	Type species: Parabolia megae gen. et sp. nov.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	description	(Fig. 11)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	materials_examined	Material examined: Six specimens, two sagittally sectioned. Holotype: AM W. 50281 (23 slides). Paratypes: AM W. 50282 (8 slides); AM W. 50278, W. 50280, W. 50283, W. 50284 (wet material). Type locality: Australia, New South Wales, Toowoon Bay, rocky headland adjacent to SLSC, found under rocks, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 16 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	etymology	Etymology: The specific name is dedicated to the Marine Ecology Group (MEG) of Macquarie University, Sydney, Australia.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	description	Description: Body oval with rounded ends. Fixed specimen 1.3 cm long. Paratypes 1.2 to 1.3 cm long. Dorsal surface with pale cream colour and reddish-brown web-like pattern, darker around the pharyngeal region and tentacles (Fig. 11 A). Small tentacles present. Tentacular eyes inside the tentacles, cerebral eyes located in two elongated parallel clusters above brain area (Fig. 11 E, F). Ruffled pharynx located anterior to middle part of the body, oral pore opening in its centre (Fig. 11 B, C). Male and female gonopores located close together immediately behind pharynx. Male copulatory apparatus enclosed in a muscular bulb consisting of a seminal vesicle, interpolated prostatic vesicle and a penis papilla armed with a complex, parabolic dish-like stylet, directed backwards (Fig. 11 C, D, G – K). Ventral fibres of the muscular bulb mix together with the ventral wall anchoring the whole system to the ventral side of the animal. Vasa deferentia run ventrally towards the pharyngeal region before looping back towards the male system in an M-shape formation, swelling into spermiducal bulbs before joining distally the seminal vesicle (Fig. 11 D). Seminal vesicle oval-shaped, enclosed inside the muscular bulb and covered with a thick muscular layer (Fig. 11 K). Ejaculatory duct projects distally into the glandular epithelium of the prostatic vesicle. Prostatic vesicle provided with a strong muscular layer and lined with thick ridged glandular epithelium (Fig. 11 F – I). Distal end of prostatic vesicle covered with the same cuticular material present in the penis stylet. Ejaculatory duct leaves the prostatic vesicle proximally and coils forming a loop before joining the stylet. The complex penis stylet has two different parts: a semi-spherical, parabolic dish-like structure and a conical pointed end extruding from its centre (Fig. 11 G, I – K). The parabolic dish-like structure presents a serrated surface on the exterior. Male atrium divided in two sections, one non ciliated housing the penis stylet and provided with circular muscle layers clearly separated from the musculature of the prostatic vesicle and the muscular bulb, and another larger and ciliated provided with a glandulo-muscular fold (Fig. 11 G – K). Female system located dorsal to the male apparatus. Vagina externa thickened, running dorsally and looping over the male system before receiving the oviducts (Fig. 11 G – J). Lang’s vesicle absent.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	discussion	Remarks: Parabolia megae gen. et sp. nov. shares some of the morphological characteristics of the Gnesiocerotidae Marcus & Marcus, 1966 and Cryptocelidae Laidlaw, 1903 families sensu Faubel 1983. Parabolia megae gen. et sp. nov. presents an interpolated prostatic vesicle lined with ridged glandular epithelium, a trait it shares in common with genera from both families. However, the ejaculatory duct of P. megae gen. et sp. nov. projects inside the glandular epithelium of the prostatic vesicle unlike the case present in genera from the abovementioned families. Parabolia megae gen. et sp. nov. is provided with a muscular bulb enclosing its male reproductive system similar to those present in Gnesiocerotidae, yet these are much more heavily muscularised in Gnesiocerotidae genera than in P. megae gen. et sp. nov. The muscular bulb of P. megae gen. et sp. nov. appears anchored to the ventral side of the animal unlike those present in Gnesiocerotidae genera. Furthermore, the seminal vesicle of P. megae gen. et sp. nov. appears enclosed inside the muscular bulb, a trait that has not been described for any other family. Parabolia megae gen. et sp. nov. presents a male reproductive system armed with a complex penis stylet. In Cryptocelidae, only two genera have armed male copulatory systems, Macginitiella Hyman, 1953 and Hylocelis Faubel, 1983. The former possesses a regular penis stylet while the latter is provided with a central cuticular tooth surrounded by two “ spoon-shaped ” cuticular areas on each side of the cirrus bulb. Meanwhile, Gnesiocerotidae genera are characterised by the presence of a cirrus armed with spines and hooks (Echinoplana Haswell, 1907; Styloplanocera Bock, 1913), a cirrus cuticularly lined without spines, teeth or hooks (Planctoplanella Hyman, 1940) or a male copulatory system with a “ complicated cuticularized penis ” (Gnesioceros Diesing, 1862). The complicated penis described for Gnesioceros consists of a finger-like organ composed of parallel toothed narrow clasps made of cuticular-like material (Faubel 1983). None of the structures present among these genera resemble the complex parabolic dish-like structure of the stylet of Parabolia gen. nov. Parabolia megae gen. et sp. nov. presents a heavily muscularised male atrium divided in two sections, with the most exterior one provided with a glandulo-muscular fold. The presence of glandular fibres inside this muscular bulb implies the existence of extra-vesicular masculine secretions. These fibres are clearly different from other glandular organs such as prostatoids or adenodactils present in other polyclad flatworms. While the presence or absence of a Lang’s vesicle is a variable trait among polyclad genera, including the Gnesiocerotidae and Cryptocelidae families, the presence of a female system extending dorsally over the male system is a unique characteristic not present in any other genera of these two families. Likewise, the presence of tentacles is a variable characteristic among genera from both Gnesioceridae and Cryptocelidae. Molecular remarks: Parabolia megae gen. et sp. nov. appeared nested within the Leptoplanoidea superfamily with strong support (95 / 0.96) and as part of a clade with Gnesioceros sargassicola (Mertens, 1833), Ceratoplana falconerae sp. nov. and Phaenoplana kopepe Oya & Kajihara, 2019 with high support (90 / 1.00). This clade appeared as most closely related to another clade formed by Styloplanocera fasciata (Schmarda, 1859), Comoplana agilis (Lang, 1884), Stylochoplana clara Kato, 1937 and Echinoplana celerrima Haswell, 1907 with strong BS support (73) in the ML analysis. The clade in the Bayesian analysis has lower support (0.57) and includes Neostylochus ancorus sp. nov. Oya & Kajihara (2020) considered the possibility of Gnesiocerotidae Marcus & Marcus, 1966 being a junior synonym of Stylochoplanidae Meixner, 1907 and refrained from redefining the family until data of the nominal species of the genus Stylochoplana was made available. The close relationship between Gnesiocerotidae and Stylochoplanidae genera is also clearly evident in our molecular results yet not fully resolved. As such, based on our current data we placed Parabolia gen. nov. within the Gnesiocerotidae family as it appeared in the same clade as the nominal species of its nominal genus Gnesioceros, G. sargassicola (Mertens, 1833), while a species belonging to the nominal genus Stylochoplana, S. clara Kato, 1937, appeared in a separate clade. Genus Echinoplana Haswell, 1907	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	diagnosis	Diagnosis (after Faubel 1983): Gnesiocerotidae with eyes in elongate cerebral clusters; tentacles lacking. Separate male and female reproductive apertures. Male copulatory apparatus with seminal vesicle and cirrus that is armed with numerous spines and hooks. Female apparatus with vagina bulbosa and bursa copulatrix; Lang’s vesicle rudimentary.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF160260C69EC28D9FCED5BEF.taxon	type_taxon	Type species: Echinoplana celerrima Haswell, 1907.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15D260F69EC2BC9FB3F5B3B.taxon	description	(Fig. 12)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15D260F69EC2BC9FB3F5B3B.taxon	materials_examined	Material examined: Several specimens, one sagittally sectioned. AM W. 50263 (8 slides), W. 50289 (10 slides), W. 51292 (3 slides); AM W. 50260, W. 50264, W. 50269, W. 50273, W. 50279, W. 50289, W. 50290, W. 50291, W. 51318, W. 51319, W. 51320, W. 51323, W. 51325, W. 51331, W. 51332, W. 51334, W. 51335, W. 53216 (wet material). Specimens were found under rocks at low tide, collected from Australia, New South Wales: Minnie Waters 29 ° 46 ’ 34.8 ” S, 153 ° 18 ’ 08.6 ” E. Coll. Jorge Rodriguez and Justin McNab, December 6 th, 2019; Diggers Camp 29 ° 49 ’ 01.6 ” S, 153 ° 17 ’ 34.4 ” E. Coll. Jorge Rodriguez and Justin McNab, December 8 th, 2019; Port Macquarie 31 ° 27 ’ 27.7 ” S 152 ° 56 ’ 04.4 ” E,. Coll. Jane Williamson and Louise Tosetto, January 8 th, 2020; Catherine Hill Bay, Middle Camp Beach 33 ° 8 ’ 45.93 ” S, 151 ° 38 ’ 18.00 ” E. Coll. Alex Hegedus and Jorge Rodriguez, May 14 th, 2018; Norah Head rock platform; Toowoon Bay, rocky headland adjacent to SLSC, found under rocks, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, May 16 th, 2018; Pulbah Island, Lake Macquarie 33 ° 5 ’ 30.19 ” S, 151 ° 35 ’ 27.65 ” E. Coll. Jorge Rodriguez, May 18 th, 2018; Bottle and Glass 33 ° 50 ’ 53.9 ” S, 151 ° 16 ’ 12.3 ” E. Coll. Jorge Rodriguez and Justin McNab, October 25 th, 2019 & February 21 st, 2020; Chowder Bay, Sydney Harbour 33 ° 50 ’ 20.1 ” S, 151 ° 15 ’ 16.8 ” E. Coll. Jorge Rodriguez, Justin McNab, Stephanie Bagala and Audrey Watson, February 21 st, 2020; Boat Harbour, Gerroa 34 ° 45 ’ 02.0 ” S, 150 ° 49 ’ 56.5 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 7 th, 2018; Shelly Beach, Eden 37 ° 04 ’ 22.0 ” S, 149 ° 54 ’ 45.6 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 10 th, 2018. Victoria: Cape Paterson 38 ° 40 ’ 28.6 ” S, 145 ° 37 ’ 16.5 ” E. Coll. Jorge Rodriguez, March 25 th, 2019; Cats Bay, Phillip Island 38 ° 30 ’ 24.6 ” S, 145 ° 07 ’ 33.8 ” E. Coll. Jorge Rodriguez, Patrick Burke and Louise Tosetto, July 12 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15D260F69EC2BC9FB3F5B3B.taxon	discussion	Remarks: Echinoplana celerrima possesses an elongated body shape and is characterised by the presence of a cirrus provided with numerous spines that is externally visible as a thin and often twisted brown line positioned behind the pharynx (Fig. 12 A – F). Echinoplana celerrima is currently the most widespread intertidal polyclad species known in southeastern Australia. Specimens belonging to this species have been rarely found in the Mediterranean Sea, which contrast with their abundance along the southeastern Australian coast. One possible explanation for this occurrence might be that specimens of E. celerrima were transported by ships from Australia to the Mediterranean Sea where they found appropriate conditions to settle. Transportation via shipping or ballast waters could be a reasonable explanation for the seemingly cosmopolitan distribution of some polyclad species (Merory & Newman, 2005). Molecular remarks: Echinoplana celerrima appeared together with another specimen from Tunisia sequenced by Dittmann et al. (2019) with high support (100 / 1.00) and short branch lengths, providing further evidence that both Australian and Mediterranean populations belong to the same species. The Echinoplana clade is located within the Leptoplanoidea superfamily but its position within it is not fully resolved. This genus is currently placed within the Gnesiocerotidae family yet Oya & Kajihara (2020) recovered Echinoplana celerrima as more closely related to genera like Leptoplana Ehrenberg, 1831, Notoplana Laidlaw, 1903, and Notocomplana Faubel, 1983 than Gnesioceros Diesing, 1862, and therefore noting that Echinoplana should not be placed within Gnesiocerotidae. In this study Echinoplana was recovered in a clade with Styloplanocera Bock, 1913, Comoplana Faubel, 1983, and Stylochoplana (Schmarda, 1859) in the ML analysis with strong support (75), and also with Neostylochus ancorus sp. nov. in the Bayesian analysis with high support (1.00), while Gnesioceros Diesing, 1862, Phaenoplana Faubel, 1983, Parabolia gen. nov., and Ceratoplana Bock, 1925 a clustered together as sister taxa (73 / 0.57). However, even though the Gnesiocerotidae family was still recovered as paraphyletic, Echinoplana celerrima was clearly separated from the previous genera mentioned by Oya & Kajihara (2020).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15D260F69EC2BC9FB3F5B3B.taxon	distribution	Distribution: Australia: Port Jackson, New South Wales, (Haswell 1907, type locality); Italy (Galleni 1978); New Zealand: North Island (Holleman 2007); Tunisia: lagoon of Tunis (Gammoudi et al. 2009).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	description	(Fig. 13)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	materials_examined	Material examined: One specimens sagittally sectioned. NMV F 248134.1 – F 248134.3 (3 slides). Specimen collected from Australia, Victoria, Cape Paterson, Boat Ramp area, found intertidally on the blades of the seagrass Amphibolis antarctica, 38 ° 40 ’ 28.6 ” S, 145 ° 37 ’ 16.5 ” E. Coll. Audrey Falconer and Jorge Rodriguez, March 25 th, 2019.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	discussion	Remarks: The studied specimen agreed with the original description from Kato (1937 a). Externally, the specimens are of similar small size (5 mm long), with a broad and rounded anterior part of the body, nuchal tentacles with few (2 – 3) tentacular eyes and a light green colouration with visible intestinal and reproductive systems (Fig. 13 A – C). The studied specimens also present small circular spots of white pigment evenly distributed around the anterior margin that are not mentioned in the original description. The pharynx is located in the middle of the body and appears poorly plicated, with the mouth opening in the hind end (Fig. 13 B). The male apparatus is provided with an oval-shaped seminal vesicle with a thick muscular layer, an elongated and greatly enlarged prostatic vesicle lined with tall smooth glandular epithelium, and a long and muscular unarmed penis papilla. The female system presents a thickened vagina externa provided with a small protrusion that Kato (1937 a) describes as a bursa copulatrix. The vagina interna loops dorsally over the male copulatory system before receiving the oviducts and is provided with an oval Lang’s vesicle (Fig. 13 B, D, E). Kato (1937 a) notes that this species was commonly found living on the seagrass Zostera and Phyllospadix, while the specimens from this study were found on a similar wide-leafed seagrass, Amphibolis antarctica. Molecular remarks: Stylochoplana clara appeared nested within the Leptoplanoidea superfamily with strong support (95 / 0.96) and as part of a common clade with Styloplanocera fasciata (Schmarda, 1859), Comoplana agilis (Lang, 1884) and Echinoplana celerrima Haswell, 1907 with strong BS support (73) in the ML analysis while the Bayesian analysis had lower support (0.57) and included Neostylochus ancorus sp. nov. This clade appeared as most closely related to another clade formed by Parabolia megae gen. et sp. nov., Gnesioceros sargassicola (Mertens, 1833), and Phaenoplana kopepe Oya & Kajihara, 2019 with high support (90 / 1.00).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	distribution	Distribution: Japan: Misaki (Kato 1937), Susaki near Simoda (Kato 1944). New record: Australia, Victoria, Cape Paterson. Genus Ceratoplana Bock, 1925 a	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	diagnosis	Diagnosis (after Faubel 1983): Stylochoplanidae with well-developed oblong tentacles. Mouth arranged far behind the centre of the very long pharyngeal cavity. Seminal vesicle immediately behind the pharynx. Lining epithelium of the prostatic vesicle provided with cilia. Penis long, narrow and unarmed. Gonopores separated. Female apparatus with ductus vaginalis. Vagina interna and ductus vaginalis open into a common female atrium. Lang’s vesicle lacking.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC290EFCCC5BFE.taxon	type_taxon	Type species: Ceratoplana colobocentroti Bock, 1925 a.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC2BC9FC9B5DE0.taxon	diagnosis	Diagnosis (after Faubel 1983): Stylochoplanidae with or without tentacles; eyes in paired cerebral and tentacular or cerebro-tentacular clusters. Male copulatory apparatus with conical papillate penis and true seminal vesicle. Female apparatus with Lang’s vesicle. Gonopores separate.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF15B260969EC2BC9FC9B5DE0.taxon	type_taxon	Type species: Stylochoplana maculata (Quatrefages, 1845).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	description	(Fig. 14)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	materials_examined	Material examined: Three specimens, two sagittally sectioned. Holotype: NMV F 248135.1 – F 248135.4 (4 slides). Additional material: AM W. 51327 (2 slides). AM W. 53223 (wet material). Type locality: Australia, Victoria, Cape Paterson, Boat Ramp area, found intertidally on the blades of the seagrass Amphibolis antarctica, 38 ° 40 ’ 28.6 ” S, 145 ° 37 ’ 16.5 ” E. Coll. Audrey Falconer and Jorge Rodriguez, March 25 th, 2019. Additional material locality: Australia, Victoria, Cats Bay, Phillip Island 38 ° 30 ’ 24.6 ” S, 145 ° 07 ’ 33.8 ” E. Coll. Jorge Rodriguez, Patrick Burke and Louise Tosetto, July 12 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	etymology	Etymology: The specific name is dedicated to Ms. Audrey Falconer of the Field Naturalists’ Club of Victoria for her invaluable help in conducting fieldwork in the state of Victoria.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	description	Description: Body oval with expanded anterior region and pointed posterior end. Length 0.9 cm. Dorsal surface greyish-brown with scattered dark brown and cream spots and semi-transparent body margin interrupted by light brown spots; region above pharynx with cream colour and small brown pigments (Fig. 14 A). Nuchal tentacles present. Tentacular eyes inside tentacles, cerebral eyes located in two elongated parallel clusters above brain area (Fig. 14 B, D). Ruffled pharynx located anterior to middle part of the body, oral pore opening in its centre (Fig. 14 B, C). Male and female gonopores located separate behind pharynx. Male copulatory apparatus consists of a seminal vesicle, an interpolated prostatic vesicle and a penis papilla, directed backwards (Fig. 14 E – G). Vasa deferentia run ventrally and join distally seminal vesicle (Fig. 14 F). Seminal vesicle S-shaped and provided with a strong muscular layer (Fig. 14 F). Ejaculatory duct narrows into a thin tube and joins distally prostatic vesicle. Prostatic vesicle and penis papilla included in a muscular penis sheath. Oval prostatic vesicle provided with a muscular layer and lined with smooth glandular epithelium (Fig. 14 G). Penis papilla conical-shaped and directly connected to prostatic vesicle, provided with a strengthening at the distal tip formed by the base membrane (also referred to as penis sheath) and housed in a ciliated male atrium (Fig. 14 G). Female system located posterior to male apparatus (Fig. 14 E, H, I). Vagina externa runs vertically reaching dorsal side of the animal (Fig. 14 H), connects with vagina interna and loops ventrally and anteriorly towards male system before turning back posteriorly and receiving oviducts (Fig. 14 I). End of vagina interna connects back to its middle region through a ductus vaginalis, forming a loop (Fig. 14 H), Lang’s vesicle absent. Female gonopore and ductus vaginalis share a common female atrium.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	discussion	Remarks: The presence of a well-defined seminal vesicle, an interpolated prostatic vesicle with smooth glandular epithelium, and an unarmed penis papilla positions the new species in the Stylochoplanidae family. Among all Stylochoplanidae genera, the new species aligns best with the genus Ceratoplana Bock, 1925 a due to its long pharyngeal cavity with the mouth opening in its anterior region, separate gonopores, presence of a well-defined seminal vesicle, an interpolated prostatic vesicle with smooth glandular epithelium, an unarmed penis papilla, a female system provided with a ductus vaginalis that loops back into the vagina interna, and Lang’s vesicle lacking. Ceratoplana falconerae sp. nov. can be distinguished from Ceratoplana colobocentroti Bock, 1925 a, the type and only other species of the genus, by the presence of a short penis papilla provided with a penis sheath (also referred to as a strengthening at the distal tip by a styliform developing of the base membrane by Faubel (1983 )). The presence of a penis sheath is currently considered to be diagnostic character of specific level in another Stylochoplanidae genus, Emprosthopharynx Bock, 1913. In comparison, C. colobocentroti presents a very long and narrow penis papilla housed in a tall male atrium. Molecular remarks: Ceratoplana falconerae sp. nov. appeared nested within the Leptoplanoidea superfamily with strong support (95 / 0.96) and as part of a common clade with Parabolia megae gen. et sp. nov., Gnesioceros sargassicola (Mertens, 1833), and Phaenoplana kopepe Oya & Kajihara, 2019 with high support (90 / 1.00). This clade appeared as most closely related to another clade formed by Styloplanocera fasciata (Schmarda, 1859), Comoplana agilis (Lang, 1884), Stylochoplana clara Kato, 1937 and Echinoplana celerrima Haswell, 1907 with strong BS support (73) in the ML analysis while the Bayesian analysis had lower support (0.57) and included Neostylochus ancorus sp. nov.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF159260B69EC2BC9FB3B5BC2.taxon	distribution	Distribution: Australia, Victoria: Cape Paterson, Boat Ramp area; Cats Bay, Phillip Island.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260769EC29FDFEAD5D5E.taxon	description	(Fig. 15)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260769EC29FDFEAD5D5E.taxon	materials_examined	Material examined: Several specimens, one sagittally sectioned. AM W. 51324 (10 slides); AM W. 51336, W. 51337, W. 51338, W. 51339, W. 53215 (wet material). Specimens were collected from Australia, New South Wales: Shelly Beach, Eden, 37 ° 04 ’ 22.0 ” S, 149 ° 54 ’ 45.6 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 10 th, 2018. Victoria: Cape Paterson, 38 ° 40 ’ 28.6 ” S, 145 ° 37 ’ 16.5 ” E. Coll. Jorge Rodriguez, March 25 th, 2019 and Cats Bay, Phillip Island, 38 ° 30 ’ 24.6 ” S, 145 ° 07 ’ 33.8 ” E. Coll. Jorge Rodriguez, Patrick Burke and Louise Tosetto, July 12 th, 2018. Additional material from Australia, New South Wales, Long Reef from the collections of the Australian Museum: AM W. 3691. Additional material from Australia, South Australia, Bird Bay from the collections of the South Australian Museum: AHC. 42639 – 42645.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260769EC29FDFEAD5D5E.taxon	discussion	Remarks: The studied specimens agreed with the descriptions given by Haswell (1907), Bock (1913), Hyman (1959) and Prudhoe (1982). As noted by Haswell (1907) and Prudhoe (1982), Notoplana australis appeared to be a quite common polyclad on the southeastern Australian coasts. Although not as widely distributed as Echinoplana celerrima, more than 30 specimens were found on a single day at Eden (New South Wales) and it was also quite common (~ 20 specimens) around Inverloch (Victoria). The colouration of the dorsal surface varied from different shades of brown, orange, olive-grey, greenish grey to almost black as stated by both Hyman (1959) and Prudhoe (1982). Regarding the internal anatomy, the male copulatory system consists of a seminal vesicle, an interpolated prostatic vesicle with chambered glandular epithelium and a penis armed with a long and slender stylet. Hyman (1959) remarks on the presence of numerous convolutions in the vagina that correspond to the morphology present in the studied specimen. Molecular remarks: Notoplana australis appeared most closely related to another specimen of the same species from Port Phillip Bay, Victoria sequenced by Litvaitis et al. (2019) with high support (100 / 1.00). The N. australis clade appeared inside another one including Amyris hummelincki, Leptoplana tremellaris and Notoplana felis sp. nov. with low support (68 / 0.76) and appearing as a polytomy in the BI analysis. The genus Notoplana appeared as paraphyletic with N. delicata and N. atomata more closely related to the Notocomplana clade and N. queruca clustering with Notocomplana ferruginea in a separate clade.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260769EC29FDFEAD5D5E.taxon	distribution	Distribution: Australia: Victoria, Port Phillip (Laidlaw 1904, type locality), New South Wales, Port Jackson (Haswell 1907), Jervis Bay (Haswell 1907), Long Reef, near Collaroy (Hyman 1959), South Australia, Jones Island, Bird Bay (Prudhoe 1982), Daly Head, Yorke Peninsula (Prudhoe 1982), Brown Point, Yorke Peninsula (Prudhoe 1982), Wittelbee Point (Prudhoe 1982), American River Inlet, Kangaroo Island (Prudhoe 1982), Port Noarlunga, St. Vincent Gulf (Prudhoe 1982), Tipara Reef, Spencer Gulf (Prudhoe 1982), Tasmania (Haswell 1907); New Zealand: Lyttleton Harbour northwards to Auckland Harbour (Schmarda 1859; Jacubowa 1906; Haswell 1907), North Island (Holleman 2007).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260569EC2BC9FCF25E4D.taxon	diagnosis	Diagnosis: Notoplanidae with tentacular and cerebral eye clusters. The pharynx is arranged more or less anterior to the middle of the body. Gonopores separate. Male copulatory apparatus consists of seminal vesicle and armed penis; elongate male atrium housing the penis stylet. Female apparatus with Lang’s vesicle. External vagina may be developed as vagina bulbosa.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF157260569EC2BC9FCF25E4D.taxon	type_taxon	Type species: Notoplana dubia (Schmarda, 1859).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF155260669EC2ACCFCE15FF2.taxon	description	(Fig. 16)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF155260669EC2ACCFCE15FF2.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 53210 (4 slides). A specimen was collected at low tide under rocks from Australia, New South Wales, Bottle & Glass, 33 ° 50 ’ 53.9 ” S, 151 ° 16 ’ 12.3 ” E. Coll. Jorge Rodriguez and Justin McNab, October 25 th, 2019. Additional material from Australia, New South Wales, Long Reef from the collections of the Australian Museum: AM W. 3693 (holotype), W. 3694. Notoplana longicrumena Prudhoe, 1982. One specimen from the collections of the Australian Museum, sagittally sectioned. AM W. 53211 (8 slides). The specimen was collected from Australia, Tasmania, Pirates Bay Reef, March 7 th, 1958. Additional material from Australia, South Australia, Point Brown from the collections of the South Australian Museum: AHC. 42652 – 42668 (holotype).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF155260669EC2ACCFCE15FF2.taxon	discussion	Remarks: Externally, Notoplana longiducta Hyman, 1959 possesses an elongated body shape with a pale brown dorsal colouration, a transparent body margin and an anteriorly positioned pharynx (Fig. 16 A – D). Internally, N. longiducta is characterised by the presence of a seminal vesicle, interpolated prostatic vesicle lined with tubularly chambered glandular epithelium, a very elongated penis stylet and a simple female system with a vertically oriented Lang’s vesicle (Fig. 16 E – I). Hyman (1959) mentions the poor state of the male copulatory system in the histological sections and the difficulties it caused in reconstructing its anatomy. In the original description Hyman (1959) describes Notoplana longiducta as having an elongated and pointed penis papilla; however, a revision of the type material made clear that what was described as a penis papilla was in fact a fold of the male atrium (Fig. 16 I). Hyman (1959) mentions not only that the histological sections are in poor condition but that the cuts were not performed in an exact sagittal plane, which explains the misidentification of this trait. It was also apparent in both the holotype and the specimen from Bottle & Glass that this species presents a stylet in its male copulatory organ, although it was overlooked in the original description due to the poor condition of the type material (Fig. 16 I). Faubel (1983) transferred Notoplana longiducta to the new genus Notocomplana created for Notoplana species not bearing a stylet. However, a re-examination of the holotype and new material revealed the presence of such trait in the male copulatory organ. As such, the present species was transferred back to Notoplana under the original combination Notoplana longiducta. Prudhoe (1982) described the new species Notoplana longicrumena from Point Brown, South Australia based on the presence of a long and slender penis stylet. Re-examination of the type material showed that the internal anatomy was identical to that of N. longiducta in light of the new description (Fig. 16 G). As such, the primary authority belongs to Hyman (1959) and N. longicrumena was synonymised with N. longiducta.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF155260669EC2ACCFCE15FF2.taxon	distribution	Distribution: Australia: New South Wales, Long Reef (Hyman 1959), South Australia, Point Brown (Prudhoe, 1982). New record: Australia, Tasmania, Pirates Bay Reef.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	description	(Fig. 17)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	materials_examined	Material examined: One specimen sagittally sectioned. Holotype: AM W. 51326 (15 slides). Notoplana longisaccata Hyman, 1959. AM W. 3692 (holotype). Type locality: Australia, Victoria, Cats Bay, Phillip Island, 38 ° 30 ’ 24.6 ” S, 145 ° 07 ’ 33.8 ” E. Coll. Jorge Rodriguez, Patrick Burke and Louise Tosetto, July 12 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	etymology	Etymology: The specific name refers to the Latin term for “ cat ” as a reference to the place where it was discovered, Cat Bay.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	description	Description: Body elongated with rounded ends. Length 1.2 cm. Dorsal surface pale cream (Fig. 17 A). Tentacular eyes present in two clusters, cerebral eyes located in two elongated parallel clusters above brain area (Fig. 17 A, C). Ruffled pharynx located anterior to the middle of the body, oral pore opening posterior to its centre (Fig. 17 B). Male and female gonopores located separate behind pharynx. Male copulatory apparatus consists of a seminal vesicle, an interpolated prostatic vesicle and an armed penis papilla with a short and slender stylet, directed backwards (Fig. 17 D – H). Vasa deferentia run ventrally and joins distally seminal vesicle. Seminal vesicle ovalshaped and provided with a strong muscular layer (Fig. 17 G). Ejaculatory duct joins distally prostatic vesicle and projects into its lumen (Fig. 17 G). Oval prostatic vesicle provided with a strong muscular layer, lined with tubularly chambered glandular epithelium and provided with extra-vesicular glands (Fig. 17 G). Penis papilla short, thick and conical-shaped, armed with a slender stylet and housed in a penis-pocket (Fig. 17 E, H). Female system located posterior to male apparatus (Fig. 17 D, H). Thick vagina externa runs vertically, connects with vagina interna and loops anteriorly towards male system before turning back posteriorly and receiving oviducts (Fig. 17 H). End of vagina interna connects with Lang’s vesicle, reaching the hind end of the animal (Fig. 17 H).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	discussion	Remarks: The new species belongs to the genus Notoplana due to the presence of a pharynx positioned anterior to the middle of the body, male copulatory system with an interpolated prostatic vesicle lined with tubularly chambered glandular epithelium and an armed penis papilla with a stylet, and a female system with Lang’s vesicle. Notoplana felis sp. nov. most closely resembles another Australian Notoplana species, N. longisaccata Hyman, 1959. Notoplana longisaccata possesses a wide pharynx situated in the middle of the body compared to the slender and anteriorly positioned pharynx of N. felis sp. nov. Both N. longisaccata and N. felis sp. nov. present short and armed penis papillae; however, the penis papilla of N. longisaccata is slender while that of N. felis is thick and conical-shaped. The main difference between both species is the presence of an exceedingly long Lang’s vesicle in N. longisaccata (about 1 / 6 of the length of the preserved worm), while that of N. felis is the same size as the rest of the female system. Molecular remarks: Notoplana felis sp. nov. appeared in a clade including Notoplana australis, Amyris hummelincki and Leptoplana tremellaris with low support (68 / 0.76) and appearing as a polytomy in the BI analysis. The genus Notoplana appeared as paraphyletic with N. delicata and N. atomata more closely related to the Notocomplana clade and N. queruca clustering with Notocomplana ferruginea in a separate clade.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF154260069EC2F60FD3E5E23.taxon	distribution	Distribution: Known only from type locality.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC2F70FCBC5A82.taxon	description	(Fig. 18)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC2F70FCBC5A82.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 51330 (15 slides). A specimen was collected at low tide under rocks from Australia, Victoria, Cats Bay, Phillip Island 38 ° 30 ’ 24.6 ” S, 145 ° 07 ’ 33.8 ” E, coll. Jorge Rodriguez, Patrick Burke and Louise Tosetto, July 12 th, 2018.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC2F70FCBC5A82.taxon	discussion	Remarks: The studied specimen agreed with the original description by Prudhoe (1982). Externally, Notocomplana distincta (Prudhoe, 1982) comb. nov. possesses an elongated body shape with a pale cream dorsal colouration and an anteriorly positioned pharynx (Fig. 18 A, B, D). Internally, N. distincta is characterised by the presence of a seminal vesicle, interpolated prostatic vesicle lined with tubularly chambered glandular epithelium, an elongated penis papilla housed in a penis-pocket and a simple female system with narrow vagina externa and circular Lang’s vesicle (Fig. 18 E, F). Faubel (1983) created the genus Notocomplana to separate Notoplana species without a penis stylet. As such, Notoplana distincta was transferred to Notocomplana under the new combination Notocomplana distincta.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC2F70FCBC5A82.taxon	distribution	Distribution: Australia, South Australia, St. Vincent Gulf, Port Noarlunga (Prudhoe 1982, type locality). New record: Australia, Victoria, Cats Bay, Phillip Island.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC29D0FCC95FC2.taxon	diagnosis	Diagnosis: Notoplanidae with paired tentacular and cerebral eye clusters. Tentacles usually lacking. Gonopores separate. Male copulatory apparatus consists of a true seminal vesicle and an elongate or blunt conical penis papilla. Female apparatus with Lang’s vesicle. External vagina with tendency to a stronger muscle wall (vagina bulbosa).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260069EC29D0FCC95FC2.taxon	type_taxon	Type species: Notocomplana humilis (Stimpson, 1857).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260369EC2DB0FD195D02.taxon	diagnosis	Diagnosis (after Faubel 1983, emended): Pseudostylochidae with elongated body outline. Eyes in paired tentacular and cerebral clusters; marginal eye-spots lacking; tentacles present. Pharynx oriented anterior; mouth in front of the centre of the body. Gonopores separate. Male complex located in the last third of the body, with seminal vesicle and penis papillae. Male atrium very muscular. Female apparatus with ductus vaginalis, hence Lang’s vesicle lacking. Ductus vaginalis opens ventral and behind the female gonopore to the exterior.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF152260369EC2DB0FD195D02.taxon	type_taxon	Type species: Tripylocelis typica Haswell, 1907.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2DC3FCC45BE9.taxon	diagnosis	Diagnosis (after Faubel 1984): Diposthidae with cerebral and tentacular eye-spots. Sucker lacking. Tentacles present. Male copulatory complex directed perpendicularly; without true seminal vesicle but spermiducal bulbs present: penis papillate. Uterine vesicles probably present.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2DC3FCC45BE9.taxon	type_taxon	Type species: Diposthus corallicola Woodworth, 1898.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2A30FDF55A70.taxon	description	(Fig. 19)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2A30FDF55A70.taxon	materials_examined	Material examined: Several specimens, two sagittally sectioned. AM W. 50268 (3 slides), W. 51333 (3 slides, wet material). Specimens were collected from Australia, New South Wales: Minnie Waters 29 ° 46 ’ 34.8 ” S, 153 ° 18 ’ 08.6 ” E. Coll. Jorge Rodriguez and Justin McNab, December 6 th, 2019; Port Macquarie 31 ° 27 ’ 27.7 ” S 152 ° 56 ’ 04.4 ” E. Coll. Jane Williamson and Louise Tosetto, January 8 th, 2020; Norah Head rock platform, 33 ° 16 ’ 43.14 ” S, 151 ° 34 ’ 12.85 ” E, Toowoon Bay, 33 ° 21 ’ 47.01 ” S, 151 ° 30 ’ 7.31 ” E. Coll. Jorge Rodriguez, Mandy Reid and Alison Miller, March 15 th & 16 th, 2018 and Shelly Beach, Eden, 37 ° 04 ’ 22.0 ” S, 149 ° 54 ’ 45.6 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 10 th, 2018. Additional material from Australia, New South Wales, Port Jackson from the collections of the Australian Museum: AM G. 6057.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2A30FDF55A70.taxon	discussion	Remarks: The studied specimens agreed with the original description by Haswell (1907). Externally, Tripylocelis typica presents a light brown dorsal colouration with darker brown pigments along the intestinal branches and pharynx, and a pair of nuchal tentacles on the anterior region (Fig. 19 A – D). The male copulatory system is characterised by the presence of a seminal vesicle and lack of a prostatic vesicle, where the glandular epithelium lies instead around the distal end of the ejaculatory duct before joining the penis papilla. The penis is housed in a very elongated and ciliated male atrium (Fig. 19 E, F). Haswell (1907) described the female system of T. typica with a ductus vaginalis that opens to the exterior through an accessory female pore next to the female gonopore. Prudhoe in 1982 found a specimen of this species where the ductus vaginalis loops back to the female atrium opening through a common female pore but did not consider this trait to be of specific relevance. The studied specimens of T. typica presented the morphology of the original description by Haswell (1907), were the ductus vaginalis opens next to the female atrium through an accessory female pore (Fig. 19 E, F). However, the contraction of this region due to fixation may have warped the area around the gonopores in the specimen studied by Prudhoe (1982), making it appear as a single gonopore instead of two different ones. Molecular remarks: Tripylocelis typica appeared nested within the Pseudostylochidae family with high support (98 / 1.00) together with the genera Pseudostylochus Yeri & Kaburaki, 1918 and Stylochoplanoides Bock, 1924 (as proposed by Oya & Kajihara, 2020). This differed from its original assignment to the Ilyplanidae family, represented in the Discoceloidea superfamily by the Phaenocelis and Amemiyaia clade. Therefore, this species has been transferred to the Pseudostylochidae family and the diagnosis emended.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF151260369EC2A30FDF55A70.taxon	distribution	Distribution: Australia: Port Jackson, New South Wales (Haswell 1907, type locality); Wittelbee Point, South Australia (Prudhoe 1982). Suborder Cotylea Lang, 1884	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2BC9FC2F5FBE.taxon	description	(Fig. 20)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2BC9FC2F5FBE.taxon	materials_examined	Material examined: One specimen sagittally sectioned. AM W. 53209 (5 slides). A specimen was collected at low tide under rocks from Australia, New South Wales, Bottle & Glass, 33 ° 50 ’ 53.9 ” S, 151 ° 16 ’ 12.3 ” E. Coll. Jorge Rodriguez and Justin McNab, October 25 th, 2019. Additional material from Australia, New South Wales, Long Reef from the collections of the Australian Museum: AM W. 3699 (holotype), W. 3700.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2BC9FC2F5FBE.taxon	discussion	Remarks: Hyman (1959) remarks the poor condition of the preserved specimen in the original description and the difficulties of reconstructing the male copulatory system. Based on the studied specimen from Bottle & Glass, Diposthus popeae Hyman, 1959 possesses a slender body shape with white dorsal colouration and a pair of pseudotentacles in the anterior margin (Fig. 20 A, B, D). Internally, the gonopores lie very close together, the male copulatory system is directed perpendicularly and consists of a thick and enlarged seminal vesicle and a long and slender penis papilla (Fig. 20 C, E, F). The type and only other species of the genus, D. corallicola Woodworth, 1898, from the Great Barrier Reef appears to have prostate tissue in a fold adjacent to the penis papilla and separate from the rest of the male copulatory system. In the studied specimen of D. popeae such organ cannot be found; instead, it appears the glandular function is carried out by the penis itself, having glandular tissue (Fig. 20 F) similar to the case of the ejaculatory duct of Tripylocelis typica Haswell, 1907. The female system consists of a vertically running vagina externa that turns posteriorly after connecting with the vagina interna and is provided with a circular Lang’s vesicle. A pair of cement pouches are also present (Fig. 20 F).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2BC9FC2F5FBE.taxon	distribution	Distribution: Australia, New South Wales, Long Reef (Hyman 1959).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2F67FCFA59CA.taxon	diagnosis	Diagnosis (after Faubel 1984): Pseudocerotidae with oval, elongated oval, or oblong shaped of the body. Marginal tentacles with eyes; single or paired eye clusters present. Dorsal surface covered with blunt or oblong pointed papillae which may be contractile. Male apparatus double, with seminal vesicle and armed penis papillae. Prostatic vesicle oriented antero- or medio-dorsally to the ejaculatory duct. Female apparatus with branched uteri.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261C69EC2F67FCFA59CA.taxon	type_taxon	Type species: Thysanozoon brocchii (Risso, 1818).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261F69EC2D79FC76594D.taxon	description	(Fig. 21)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261F69EC2D79FC76594D.taxon	description	figs 1, 4, 5; pl. 109, fig. 20.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261F69EC2D79FC76594D.taxon	materials_examined	Material examined: Two specimens, one sagittally sectioned. NMV F 248136.1 – F 248136.6 (6 slides); AM W. W. 53221 (wet material). Specimens were collected from Australia, Victoria, Coal Point, Harmer’s Haven 38 ° 39 ’ 18.8 ” S, 145 ° 33 ’ 57.1 ” E. Coll. Jorge Rodriguez, March 27 th, 2019.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261F69EC2D79FC76594D.taxon	discussion	Remarks: Thysanozoon brocchii can be easily distinguished from the other intertidal marine flatworms by the presence of numerous papillae on the dorsal surface and a pair of squared pseudotentacles on the anterior body margin (Fig. 21 A – C). Furthermore, Thysanozoon is also characterised by the presence of a duplicated male copulatory organ, consisting of a pair of penis papillae armed with a stylet (Fig. 21 D – F). The studied specimens presented different shades of brown background colouration with transparent margins interrupted by white spots. The dorsal papillae appeared pointed or more rounded depending on the specimen and presented the same white spots of pigmentation present along the body margin. One of the specimens also presented a white median line along the dorsal surface and on the pseudotentacles (Fig. 21 A). Thysanozoon brocchii has been described as a cosmopolitan species by Bahia et al. (2015) and Pitale & Apte (2017). Bahia states that specimens from Brazil can have slender papillae and black to greyish colouration, while the European ones present a red marginal band. Pitale & Apte (2017), after comparative examinations of different T. brocchii specimens from around the world, reached the conclusion that there exist variable colour morphs of this species, and established a series of possible colour combinations. The studied Australian specimens fit within the following categories: dorsal ground colour: brown and light brown; ground colour pattern: brown pigments, brown papillae; papillae colour pattern: white dots, margin colour transparent; margin colour pattern: white spots. Molecular remarks: The two sequenced specimens from Australia appeared together with three other specimens of Thysanozoon brocchii from Brazil (Bahia et al. 2017), Azores (Cuadrado et al. 2021) and Florida (USA) (Litvaitis et al. 2019) with high support (100 / 1.00) and short branch lengths.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14E261F69EC2D79FC76594D.taxon	distribution	Distribution: Naples, Italy (Risso 1818, type locality) and other parts of the Mediterranean Sea, United Kingdom, Algeria, Suez Canal (Palombi 1928), South and West Africa, Florida, Brazil (Bahia et al. 2012; 2014; 2015), Argentina, Borneo, Vietnam, Japan and New Zealand (Prudhoe 1985; Quiroga et al. 2004), India (Pitale & Apte 2017), Florida, Colombian Caribbean, Canary Islands (Vera et al. 2008). New record: Australia, Victoria, Coal Point, Harmer’s Haven.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14D261F69EC2EB5FC515B98.taxon	diagnosis	Diagnosis (after Faubel 1984): Prosthiostomidae with marginal eyes in varying length of the anterior margin or encircling the entire margin. Digestive system with frontally running main median intestine. Male copulatory apparatus with a pair of prostatic vesicles usually separate, arranged lateral or somewhat ventral to the ejaculatory duct; penis armed with a pointed tubular stylet.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14D261F69EC2EB5FC515B98.taxon	type_taxon	Type species: Prosthiostomum siphunculus (Delle Chiaje, 1828).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	description	(Fig. 22)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	materials_examined	Material examined: Three specimens, two sagittally sectioned. Holotype: AM W. 50286 (8 slides). Paratype: W. 50287 (10 slides). Additional material: AM W. 53224 (wet material). Type locality: Australia, New South Wales, north east side of Pulbah Island, Lake Macquarie, 33 ° 5 ’ 30.19 ” S, 151 ° 35 ’ 27.65 ” E. Coll. Jorge Rodriguez, May 18 th, 2018 Additional material locality: Australia, New South Wales, Lake Macquarie, Lake Petit, found on a settlement wood block plate, ~ 0.3 m depth amongst Zostera seagrass. Coll. Claire Rowe and Stephen Keable, October 7 th, 2020.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	etymology	Etymology: The specific name is dedicated to the Australian Museum Research Institute (AMRI), Sydney, Australia.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	description	Description: Body elongated with rounder anterior region and pointed posterior end. Length 0.7 cm. Dorsal surface translucent white with scattered light brown pigments arranged in circles; median line with two longitudinal dark brown stripes intermittently interrupted reaching the hind end of the body; anterior region above cerebral eyes with marking of same colouration as longitudinal stripes in a fan-like pattern and a transverse V-shaped white line behind cerebral eyes (Fig. 22 A, B). Tentacles absent. Cerebral eyes located in two clusters above brain area; few marginal eyes present in anterior body margin (Fig. 22 D). Tubular pharynx located anterior to middle part of the body, oral pore opening anteriorly. Sucker located behind female pore (Fig. 22 G). Male and female gonopores located separate below pharynx. Male copulatory apparatus consists of a seminal vesicle, a pair of free prostatic vesicles and an armed penis papilla with a stylet, directed backwards (Fig. 22 E – G). Vasa deferentia run ventrally and joins distally seminal vesicle. Seminal vesicle oval-shaped and provided with a strong muscular layer. Pair of oval prostatic vesicles provided with a strong muscular layer and lined with smooth glandular epithelium. Ejaculatory duct and both prostatic ducts join distally at base of penis. Penis papilla short and armed with a tubular and pointed stylet. Male copulatory organ housed in an elongated male atrium (Fig. 22 F). Female system located posterior to male apparatus. Short vagina runs vertically before joining the uterus. Cement glands concentrated around vagina and emptying their contents in cement pouch (Fig. 22 G). Lang’s vesicle absent.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	discussion	Remarks: The new species belongs to the genus Prosthiostomum due to the presence of a pair of prostatic vesicles separate from each other, a median frontal branch in the main intestine and the presence of a pointed tubular stylet. Among the 50 currently described species, Prosthiostomum amri sp. nov. most closely resembles three species with similar dorsal colouration patterns: P. trilineatum Yeri & Kaburaki, 1920, P. komaii Kato, 1944 and P. torquatum Tsuyuki, Oya & Kajihara, 2019. Prosthiostomum trilineatum presents a milky white dorsal surface with two welldefined longitudinal black bands running along either side of a median yellow stripe and a black transverse marking with a yellow border in its head region. Prosthiostomum komaii has a milky white ground colour with a slender orange yellow striation running from the cerebral region to the end of the body, with a transverse band of the same colour in front of the brain area. Lastly, P. torquatum presents a translucent dorsal surface covered with numerous orange maculae and blue dots, a single transverse narrow dark brown line running in front of the cerebral eyes, a transverse white line closely behind the dark brown line, and dark brown pigments forming a mesh-like longitudinal band mid-dorsally. Prosthiostomum amri sp. nov. can be distinguished from the previously mentioned species by the absence of spots and longitudinal bands of conspicuous colours (yellow, orange, blue). Molecular remarks: Prosthiostomum amri sp. nov. appeared in the Prosthiostomidae clade with Lurymare katoi and L. clavocapitata with high support (100 / 1.00). Prosthiostomum amri sp. nov. appeared as most closely related to L. katoi also with high support (100 / 0.98). In the original description of L. katoi there is no mention of a common muscle bulb in the male copulatory system but rather a muscular involvement of the seminal vesicle with the prostatic vesicles, defining trait that differentiates Lurymare from Prosthiostomum. Tsuyuki et al. (2019) remark there is a possibility that the presence of a common muscular bulb in the genus Lurymare might be a later ontogenetic state of development of Prosthiostomum, and thus the two genera would be synonymous. A taxonomic revision employing molecular data of the nominal species of both genera should be carried out in the future to clarify this issue.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF14A261869EC2BC9FD385BC2.taxon	distribution	Distribution: Known only from type locality.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261569EC2B81FCD05E27.taxon	diagnosis	Diagnosis (after Faubel 1984): Cestoplanidae. Sucker-like adhesive organ, if present, ventral in the hindmost end of the body. Male copulatory apparatus with true seminal vesicle and usually conical blunt penis papilla. Female apparatus with ciliated proximal vagina interna which is separately entered by uteri. Lang’s vesicle absent.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261569EC2B81FCD05E27.taxon	type_taxon	Type species: Cestoplana rubrocincta (Grube, 1840).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261469EC29D7FA6F5F95.taxon	description	(Fig. 23)	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261469EC29D7FA6F5F95.taxon	materials_examined	Material examined: Four specimens, one sagittally sectioned. AM W. 51328 (2 slides); AM W. 51329, W. 53217, W. 53222 (wet material). Specimens were collected from Australia, New South Wales: Bottle & Glass, 33 ° 50 ’ 53.9 ” S, 151 ° 16 ’ 12.3 ” E. Coll. Jorge Rodriguez and Justin McNab, October 25 th, 2019 and February 21 st, 2020, Shelly Beach, Eden, 37 ° 04 ’ 22.0 ” S, 149 ° 54 ’ 45.6 ” E. Coll. Jorge Rodriguez, Jane Williamson, Patrick Burke, Louise Tosetto and Ryan Nevatte, July 10 th, 2018. Victoria: Harmer’s Haven, Coal Point, 38 ° 39 ’ 18.8 ” S, 145 ° 33 ’ 57.1 ” E. Coll. Jorge Rodriguez, March 27 th, 2019; Cape Paterson, 38 ° 40 ’ 28.6 ” S, 145 ° 37 ’ 16.5 ” E. Coll. Jorge Rodriguez, March 25 th, 2019.	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261469EC29D7FA6F5F95.taxon	discussion	Remarks: Cestoplana rubrocincta is one of the few conspicuous intertidal marine flatworms found in southeastern Australia. This species can be easily identified by its very elongated and slender body shape and its bright orange colouration (Fig. 23 A). It is commonly found coiled in a ball when hiding under boulders. Internally, C. rubrocincta presents a male copulatory system consisting of a seminal vesicle, interpolated prostatic vesicle and a penis stylet, and a short female system provided with a cement pouch (Fig. 23 B, C). Molecular remarks: Cestoplana rubrocincta appeared closely related to another specimen from Phillip Island, Victoria, Australia (100 / 1.00), and together with another one from Lennox Heads, northern New South Wales, Australia (96 / 0.58), both sequenced by Litvaitis et al. (2019). This clade is recovered as sister taxa of another containing two specimens from Naples, Italy sequenced by Dittmann et al. (2019) and the Macaronesia (Cuadrado et al. 2021) (100 / 1.00). Both clades appear together with high support (100 / 0.96).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
2C7E87EDF147261469EC29D7FA6F5F95.taxon	distribution	Distribution: Mediterranean Sea (Grube 1840); Kenya, Africa (Laidlaw 1903 b); Porto de Sal Rei, Boa Vista Island, Cape Verde (Laidlaw 1906); Japan: Susaki near Simoda (Kato 1937 b), Kanayama (Kato 1938); Shirahamacho, Cape Bansho Zaki (Kato 1944); Italy: Naples (Kato 1944), Island of Sicilia (Kato 1944); Inca-Inca, Gaira Bay, Colombia (Quiroga 2008) and Port Jackson, New South Wales, Australia (Haswell 1907).	en	Rodríguez, Jorge, Hutchings, Pat A., Williamson, Jane E. (2021): Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa 5024 (1): 1-63, DOI: 10.11646/zootaxa.5024.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5024.1.1
