Search

Platevindex amboinae (Plate, 1893) Figs 64–69 Onchidium amboinae Plate, 1893: 177–179, pl. 7, fig. 8, pl. 11, fig. 66. Oncis coeca Plate, 1893: 199–200, pl. 7, fig. 9. Oncis lata – von Martens 1897: 128 [non Oncis lata Plate, 1893]. Oncis coeca – Stantschinsky 1907: 395. — Hoffmann 1928: 86–87. Oncis amboinae – Hoffmann 1928: 86–87. Platevindex amboinae – Dayrat 2009: 5. Material examined Lectotype (here designated) INDONESIA • lectotype (28/ 18 mm); Amboina [Ambon]; von Martens leg.; ZMB/Moll 11621a. Paralectotypes INDONESIA • 9 paralectotypes (29/20 to 18/ 12 mm); same collection data as for lectotype; ZMB/Moll 11621b. Holotype of Oncis coeca INDONESIA • holotype (27/ 16 mm) by monotypy; Amboina [Ambon]; expedition Gazelle leg.; ZMB/Moll 27446. Notes on type material Onchidium amboinae. The notum of the lectotype was cut open for the present study to examine the internal anatomy; no internal organs were removed. Three paralectotypes (29/20, 28/21 and 27/ 23 mm) are completely empty with no internal organs. Two paralectotypes (25/17 and 24/ 15 mm) were previously dissected, with their internal organs remaining except for the male parts. Four paralectotypes (24/14, 23/20, 20/15 and 18/ 12 mm) are still unopened. Oncis coeca. Parts of the posterior (female) reproductive system and of the digestive system are still present in the holotype, although they were previously dissected into pieces, likely by Plate himself. Of the male reproductive parts, only the deferent duct remains. Other material INDONESIA – Seram • 1 spec. (38/28 [2883] mm); Piru; 03°04.072′ S, 128°11.362′ E; 19 Feb. 2014; station 136; beach of palms and Acrostichum ferns behind Sonneratia mangrove; UMIZ 00105. – Halmahera • 2 specs (32/14 [5043] and 32/22 [5843] mm); Buli; 00°55.367′ N, 128°20.647′ E; 17 Mar. 2015; station 213; tall and old Rhizophora forest, high intertidal; UMIZ 00106. – Sulawesi • 5 specs (30/25, 20/20, 20/15, 18/15 and 15/ 15 mm); Luwu; M. Weber leg.; ZMB/Moll 46314 • 3 specs (25/20, 22/17 [#1] and 15/ 12 mm); SMF 333602/3. Description Color and morphology of live animals (Fig. 64) Live animals are usually not covered with mud, and their natural color is usually mostly visible without washing. The dorsal notum varies from light brown to dark brown, almost black. The hyponotum varies from grey to dark blue, almost black. The foot is yellowish-grey to dark grey (almost black). Dorsal papillae are short ( Digestive system (Figs 3 C–E, 65–66, 67A) Radulae measure up to 5.2 mm long. Examples of radular formulae are presented in Table 5. The intestinal loops are of type III, with a transitional loop oriented between 1 and 6 o’clock (Figs 3 C–E, 66A–B). The intestinal loops of the lectotype (Fig. 67A) are indistinguishable from those observed in a specimen from Sulawesi (Fig. 66B). Reproductive system (Figs 67 B–68) In the posterior part of the reproductive system, the oviduct is slightly wider than the deferent duct. Its distal section (distal to the spermatheca) is slightly shorter than its proximal section (or of the same length). The deferent duct is much longer than the oviduct, not attached to it, and highly coiled with long loops. The distal, flexible region of the penis is from 1 to 2.5 mm long and bears no hooks. The posterior retractor muscle of the penis inserts within the anterior half of the visceral cavity (and near the nervous system in specimens from Halmahera). The retractor muscle varies from approximately half the length of the penial sheath to as long as the penial sheath. The deferent duct is highly convoluted, with many loops around the penis. The deferent duct is twice as wide distally as proximally. Distinctive diagnostic features (Table 4) Externally, the lack of dorsal eyes is shared by both Platevindex amboinae and P. latus. However, the lack of dorsal eyes should be used with caution for identification because dorsal eyes often are retracted (and thus hard to see). Platevindex amboinae can be distinguished from P. latus by the presence of smaller dorsal papillae (the papillae of P. latus are larger and thorny). Internally, intestinal loops of type III are found in only two species of Platevindex, P. amboinae and P. latus. Both species, however, can be distinguished by the deferent duct in the anterior reproductive system, which seems to be slightly more convoluted in P. amboinae than in P. latus, although this should probably be evaluated with additional individuals. Based on the available data, however, P. amboinae and P. latus do not overlap geographically (Fig. 10). Distribution (Fig. 10C) Indonesia: Ambon (type locality of both Platevindex amboinae and P. coecus), Halmahera (new record) and Seram (new record). Habitat (Fig. 69) Platevindex amboinae is found on dead logs or tree trunks but not directly on mud, within a mangrove forest or in the higher intertidal adjacent to mangrove trees. It is not found on rocky shores. Remarks Onchidium amboinae needs to be transferred to the genus Platevindex due to the following combination of characters of the lectotype: flattened body, male pore slightly to the right of the midline between the ocular tentacles and no accessory penial gland. Plate (1893: 178) also indicated that there is a rectal gland in the original description, and it is clearly present in the lectotype (as in all Platevindex slugs). The absence of dorsal eyes and a short penis with no hooks mentioned by Plate (1893: 177) were confirmed by our examination of the lectotype. The hyponotum color was described as black with a white margin (1 to 1.5 mm wide), which is exactly what was observed in one of our live specimens. However, Plate (1893: 178) described an intestine of type II in Onchidium amboinae, while the intestine of the lectotype (and of all newly-collected individuals) is clearly of type III (Fig. 67A). The holotype of P. coecus (by monotypy) is characterized by a combination of traits diagnostic of species of Platevindex: a flattened body, a male opening slightly to the right of the midline between the ocular tentacles, a rectal gland and no accessory penial gland. In the original description, Plate (1893:199– 200) indicated a grayish-yellow sole and a black-blue hyponotum with a white margin, and also the absence of dorsal eyes. The only species in Ambon which lacks dorsal eyes is P. amboinae. Hoffmann (1928: 86–87) transferred Onchidium amboinae to Oncis (i.e., Platevindex) and considered Oncis coeca (i.e., Platevindex coecus) to be a synonym of Oncis amboinae (i.e., Platevindex amboinae). Labbé (1934: 234–235) agreed with Hoffmann even though he did not examine any new material. The deferent duct in the penial apparatus and in the posterior part of the reproductive system is extremely convoluted, exactly like in P. amboinae. The pieces of the intestine of the holotype were put together and are of type III, although Plate (1893: 200) described a digestive system of type II. There is no anatomical difference between the name-bearing types of Platevindex coecus and P. amboinae, both of which were described from Ambon, Indonesia. We did not find Platevindex amboinae during our mangrove survey in Ambon but we found it on the nearby island of Seram, where it seems to be rare. Platevindex amboinae was also rare in Halmahera. It may still be present in Ambon, but most likely as a rare species. Two lots previously identified as Oncis lata from Sulawesi are re-identified here as P. amboinae (ZMB/Moll 46314, SMF 333602/3). The original label for ZMB/Moll 46314 indicates that the specimens were collected in Luwu by M. Weber, which means that they are very likely the specimens which von Martens (1897: 128) identified as Oncis lata. Von Martens indicated that he examined 10 specimens. Five of those are in Berlin (ZMB/Moll 46314) and three of them are in Frankfurt-am-Main (SMF 333602/3), which were originally part of the Heidelberg collections. The specimens examined here all lack dorsal eyes, a character shared by both P. lata and P. amboinae, but they also lack the large, thorny papillae that are diagnostic of P. lata, suggesting that they belong to P. amboinae. Labbé (1934: 234–235) described a specimen (14/ 11 mm) from New Zealand which he identified as Oncis amboinae. However, if Labbé’s description is accurate, this specimen cannot be part of Platevindex amboinae or any species of Platevindex because Labbé (1934: 235) indicated that a group of dorsal eyes was present in the middle of the notum (in Platevindex, dorsal eyes are always single). It is unclear which species Labbé examined, as Onchidella is the only onchidiid genus documented so far in New Zealand. The combination of traits mentioned in the brief description (dorsal eyes, no accessory penial gland and no penial hooks), suggests it could be a Wallaconchis slug, although that is incompatible with intestinal loops of type II. Besides, Wallaconchis is not known south of New Caledonia. Most likely, as often with Labbé’s work, the locality or the description, or even both, are erroneous (Dayrat et al. 2020).

Platevindex coriaceus darwinensis Goulding & Dayrat subsp. nov. urn:lsid:zoobank.org:act: A609EB85-101E-467E-AFD5-812043EDAFFE Figs 16B, 18D, 19D, 22–25 Etymology Platevindex coriaceus darwinensis subsp. nov. is named after Darwin, Northern Territory, Australia, which is the type locality. Material examined Type material AUSTRALIA • holotype (28/26 [1700] mm); Northern Territory, Darwin, close to Tiger Brenan Rd; 12°28.782′ S, 130°54.750′ E; 19 Aug. 2012; station 69; high tidal Ceriops mangrove by small service road; NTM P.57601. Other material AUSTRALIA – Northern Territory • 3 specs (40/25 [1674], 29/21 [1663] and 20/14 [1672] mm); Darwin, Talc Head; 12°28.765′ S, 130°46.297′ E; 15 Aug. 2012; station 62; open forest of large Sonneratia alba with mud saturated with water; NTM P.57602 • 1 spec. (29/16 [1677] mm); Darwin, Near Berrimah; 12°28.786′ S, 130°54.750′ E; 16 Aug. 2012; station 63; Sonneratia, Rhizophora and Ceriops mangrove forest; NTM P.57603 • 1 spec. (32/17 [1633] mm); Darwin, near Channel Island Rd; 12°33.557′ S, 130°52.889′ E; 16 Aug. 2012; station 64; Sonneratia, Rhizophora and Ceriops mangrove forest; NTM P.57604 • 1 spec. (27/19 [1690] mm); Darwin, end of Channel Island Rd; 12°33.557′ S, 130°52.894′ E; 17 Aug. 2012; station 66; Sonneratia, Rhizophora and Ceriops mangrove forest; NTM P.57606 • 1 spec. (33/25 [1701] mm); Darwin, close to Tiger Brenan Rd; 12°28.782′ S, 130°54.750′ E; 19 Aug. 2012; station 69; high tidal Ceriops mangrove by small service road; NTM P.57608. Queensland • 1 spec. (31/26 [2549] mm); Cairns; 16°52.972′ S, 145°45.665′ E; 15 Jun. 2013; station 98; Rhizophora, Bruguiera and Ceriops, not many dead logs; MTQ • 1 spec. (50/27 [no DNA] mm); Flying Fish Point; 17°30.001′ S, 146°04.295′ E; 20 Jun. 2013; station 104; mangrove by creek with sandy mud; MTQ • 1 spec. (24/18 [2590] mm); Magnetic Island; 19°10.096′ S, 146°49.366′ E; 23 Jun. 2013; station 106; mostly Avicennia mangrove with mounds of mud; MTQ • 1 spec. (34/25 [2679] mm); Campwin Beach; 21°22.455′ S, 149°18.753′ E; 5 Jul. 2013; station 121; narrow Rhizophora mangrove with watery mud and large rocks by creek; MTQ • 2 specs (48/34 [no DNA] and 23/17 [2689] mm); Armstrong Beach; 21°27.129′ S, 149°17.084′ E; 6 Jul. 2013; station 123; margin of Rhizophora and Avicennia mangrove with open mudflat; MTQ • 1 spec. (48/29 [no DNA] mm); Queensland, Pioneer River; 21°08.511′ S, 149°12.076′ E; 8 Jul. 2013; station 125; Avicennia & Rhizophora mangrove; MTQ. INDONESIA – Halmahera • 2 specs (36/24 [5071] and 28/18 [5021] mm); Dodinga; 00°51.348′ N, 127°38.504′ E; 9 Mar. 2015; station 206; high intertidal back of mangrove with Acrostichum sp. and mounds of mud; UMIZ 00080 • 4 specs (34/19 [5112], 34/18 [5109], 22/17 [5111] and 19/13 [5110] mm); Buli; 00°55.446′ N, 128°20.612′ E; 16 Mar. 2015; station 212; logged area in front of old Rhizophora forest; UMIZ 00081. Other museum material without DNA sequences AUSTRALIA – Western Australia • 13 specs (from 35/30 to 20/ 20 mm); Kimberley, Whirlpool Pass; 16°15. 81′ S, 123°29.88′ E; on mangroves; WAM S42812 • 6 specs (from 25/25 to 17/ 15 mm); Kimberley, Cambridge Gulf, Cape Domett; 14°49.78′ S, 128°23.20′ E; WAM S26581 • 4 specs (from 35/30 to 15/ 15 mm); Exmouth Gulf, Tubridgi Point Boat Channel; 21°50.0′ S, 114°39.90′ E; WAM S26772 • 5 specs (from 30/30 to 8/ 8 mm); Exmouth Gulf, NE of Tent Point; 22°00.0′ S, 114°30.5′ E to 22°00.4′ S, 114°32.1′ E; WAM S26777. Description Color and morphology of live animals (Fig. 22) Identical to P. coriaceus coriaceus (see above), acknowledging some minor variations: the hyponotum is grey or light grey; the foot is light yellow; there are between 20 and 36 papillae with dorsal eyes, the largest animals bearing the largest numbers of eyes. Digestive system (Figs 17B, 23) Identical to that of P. coriaceus coriaceus (see above), acknowledging some minor variations: radulae measure up to 7.4 mm; examples of radular formulae are presented in Table 5; intestinal loops are of type II, with a transitional loop oriented between 6 and 8 o’clock (Fig. 17B). Reproductive system (Figs 18–19, 24) Identical to that of P. coriaceus coriaceus (see above), acknowledging some minor variations: the distal section of the oviduct (i.e., distal to the spermatheca) is long, up to two times the length of the proximal section (from the female gland mass to the spermatheca); the oviduct is much wider (up to five times) than the deferent duct; penial hooks measure from 60 to 110 μm; the flexible region of the penis with hooks is between 2 and 8 mm long (Fig. 24); the retractor muscle varies from the length of the sheath to ¼ of its length. Distinctive diagnostic features (Table 4) Platevindex coriaceus coriaceus and P. coriaceus darwinensis subsp. nov. are indistinguishable externally.The only minor difference in color variation is that a dark blue-grey hyponotum was observed in P. coriaceus coriaceus (most commonly in the Philippines) but never in P. coriaceus darwinensis subsp. nov. Internally, both subspecies can hardly be distinguished either. The ratio between the oviduct width and the deferent duct width tends to be much higher in P. coriaceus darwinensis subsp. nov. than in P. coriaceus coriaceus, but a higher variation may be discovered in the future. However, based on current data, P. coriaceus coriaceus and P. coriaceus darwinensis subsp. nov. do not overlap geographically. Distribution (Fig. 10B) Australia: Northern Territory and Queensland. Indonesia: Halmahera. Habitat (Fig. 25) Platevindex coriaceus darwinensis subsp. nov. is found in the same habitat as the nominotypical subspecies, i.e., mangrove forests, on tree roots, tree trunks and logs. It is very common in the Northern Territory (Australia) and Halmahera (Indonesia). It seems to be less common in Queensland (Australia), with Platevindex luteus found in higher abundance. Remarks A new subspecific name is needed because no existing species-group name could apply with confidence to the taxon recognized here. Platevindex cinereus was described from Broome, Western Australia, by Odhner (1917) as Oncis cinerea, exclusively known from the holotype, by monotypy, which is a small (9/ 9 mm) and immature specimen (SMNH 945). There is no doubt that the holotype of Oncis cinerea belongs to a species of Platevindex, but, because it is immature, it is not possible to determine which one. Platevindex cinereus could apply to either of the two species sampled in the Northern Territory, Australia, P. coriaceus darwinensis subsp. nov. or P. martensi, and even to the widespread species P. luteus, although the latter has not been recorded from Northern Territory or Western Australia. Because it will remain impossible to confidently apply P. cinereus to any particular species of Platevindex, it is regarded here as a nomen dubium. Some onchidiid slugs from the collections of the Western Australia Museum are identified here as P. coriaceus based on the position of their dorsal eyes and their reproductive anatomy. Whether populations of P. coriaceus from Western Australia belong to P. coriaceus coriaceus, P. coriaceus darwinensis subsp. nov., or even a distinct subspecies would have to be checked with fresh material from Western Australia. Bretnall’s (1919: 323) description of Onchidium coriaceum from Queensland does not appear to be based on Platevindex slugs: “short conical papillae” and a hyponotum “regularly yellowish” are not compatible with P. coriaceus darwinensis subsp. nov.

Platevindex latus (Plate, 1893) Figs 70–73 Oncis lata Plate, 1893: 191–192, pl. 7, fig. 2, pl. 11, fig. 59. Oncis lata – Stantschinsky 1907: 395. Platevindex latus – Dayrat 2009: 5. Material examined Lectotype (here designated) PAPUA NEW GUINEA • lectotype (27/ 27 mm); Neu-Britannien [New Britain, Papua New Guinea]; ZMB/Moll 45656a. Paralectotypes PAPUA NEW GUINEA • 3 paralectotypes (28/27, 27/24 and 23/ 26 mm); same collection data as for lectotype; ZMB/Moll 45656b. Notes on type material The lectotype was dissected for the present study and all its internal organs were left inside except for the penial complex, which was extracted and retained in a small vial. The three paralectotypes were previously dissected and are completely empty with no internal organs. All their male parts are missing. Pieces of dorsal notum, stomach, digestive gland, intestine and female gland mass remain in the jar, all mixed together, but they cannot be assigned to a particular paralectotype. Other material PAPUA NEW GUINEA • 3 specs (33/28 [#3], 32/31 [#1] and 30/25 [#2] mm); New Britain?; ZMH 27511. Description Color and morphology (Fig. 70) The color of live slugs is unknown. The preserved dorsal surface is dark brown, occasionally with lighter brown, longitudinal stripes. The preserved hyponotum is blue-grey and the foot is light yellow. Dorsal papillae are large and thorny, and do not bear dorsal eyes. Digestive system (Figs 3B, 71–72) Radulae measure up to 7.2 mm in length. Examples of radular formulae are presented in Table 5. The intestinal loops are of type III, with a transitional loop oriented between 12 and 2 o’clock (Figs 3B, 72). Reproductive system (Fig. 73) In the posterior reproductive system, the oviduct is short and approximately as wide as the deferent duct. Its distal section (distal to the spermatheca) is approximately as long as its proximal section. The deferent duct is longer than the oviduct, not attached to it, and is tightly coiled with a few short U-shaped loops. There are no hooks inside the distal, flexible region of the penis. The posterior retractor muscle inserts in the anterior half of the visceral cavity. The retractor muscle of the penis varies from approximately half the length of the penial sheath to ¾ its length. The deferent duct is highly convoluted. Distinctive diagnostic features (Table 4) Platevindex latus and P. amboinae are the only known species of Platevindex with no dorsal eyes and no penial hooks. Platevindex latus can be distinguished from P. amboinae externally by its large and thorny dorsal papillae and internally by its anterior deferent duct, which is slightly less convoluted. Distribution (Fig. 10C) Papua New Guinea: New Britain (type locality and present study). Habitat No habitat was mentioned in the original description of P. latus or on the labels of the additional material. However, P. latus likely lives on dead logs in mangroves, like its close relative P. amboinae. Remarks The flattened body and narrow foot of the lectotype of Platevindex latus clearly indicate that it belongs to Platevindex. In the original description, Plate (1893) did not mention whether a rectal gland is present or absent, but it is present in the lectotype as well as in the non-type material (it is present in all species of Platevindex). An accessory penial gland is also absent in both the lectotype and the non-type material (it is absent in all species of Platevindex). In the original description, Plate (1893: 191) described dorsal “conical granules” and indicated that “the mantle appears through them as if spiked with small thorns.” Conical papillae are present in the lectotype and all paralectotypes of P. latus as well as in the additional material from Papua New Guinea. Plate (1893: 192) described the length of the penis but did not mention penial hooks, so it can be assumed that he did not see penial hooks in the types he dissected (now paralectotypes). However, because the male parts are missing from the three paralectotypes dissected by Plate, this could not be confirmed. At any rate, penial hooks are absent in the lectotype dissected for the present study. The intestinal loops of the lectotype are of type III and Plate’s (1893: 192) description of a type II likely is a mistake, which would be consistent as he made the same error in the description of P. amboinae. Fresh material for DNA sequencing was not available. Platevindex latus was not collected during the recent MNHN expeditions in Madang and New Ireland, Papua New Guinea. Some old material discovered at the Zoologisches Museum in Hamburg seems to be part of P. latus even though its locality is uncertain (the label in the jar states “ Papua New Guinea. New Britain? Museum Godeffroy”). This material is externally identical to the lectotype (and paralectotypes) of P. latus. Plate (1893: 192) described a penis measuring 7 mm long (the proximal chondroid tube being 5 mm long and the distal, flexible region being 2 mm long). In one specimen from the Zoologisches Museum in Hamburg, the chondroid tube also measured 5 mm, but the distal region without hooks was 0.5 mm long rather than 2 mm. However, individual variation in this character occurs within species of Platevindex, and more specimens are needed to evaluate the variation for this trait within P. latus. Hoffmann (1928: 86) suggested that Platevindex latus (as Oncis lata) was a synonym of Onchidium granulosum Lesson, 1831 (type locality New Ireland, Papua New Guinea), based on the original descriptions. Although Hoffmann acknowledged that Lesson’s description was not very informative, he considered that Lesson’s description of a notum being much wider than the sole indicated that Onchidium granulosum referred to a species of Oncis (Platevindex). Labbé (1934: 234) agreed with Hoffmann. However, Lesson’s description is brief and leaves out many important details, such as whether dorsal eyes are present or not. The wide foot in Lesson’s illustration of Onchidium granulosum (Lesson 1831: pl. 14, fig. 2) does not appear to represent a species of Platevindex. The description of the habitat as a rocky shore also strongly suggests that Onchidium granulosum does not apply to a species of Platevindex, but, instead, possibly to a species of Peronia or Wallaconchis. Adams & Adams (1855: 234) transferred Onchidium granulosum to Onchidella with no justification. Because its type material could not be located and its internal anatomy was not described by Lesson, Onchidium granulosum is regarded here as a nomen dubium which applies to an onchidiid species of an unidentifiable genus. Von Martens (1897: 128) indicated that M. Weber found Oncis lata in “Celebs: M̹ndung des Flusses Djenemaedja in Luwu” [Sulawesi: mouth of the river Djenemaedja in Luwu]. Measurements were provided for the largest and smallest specimens, and the edge of the hyponotum was described as dirty yellow-gray. Von Martens indicated that the specimens are exactly the same as Plate’s (1893) description of O. lata, except for the color of edge of the hyponotum. However, when specimens from Luwu collected by M. Weber (identified as Oncis lata) were examined, they did not have the large thornlike papillae characteristic of P. lata. Thus, Sulawesi is not considered part of the geographic range of P. lata, and those specimens are identified here as P. amboinae (see that species). Bretnall’s (1919: 323) description of Oncis lata is merely a translation of Plate’s original description, except that Plate’s (1893: 191) correct statement that “eyes are missing” was changed to “eyes are present on all of the papillae.” Bretnall likely assumed that Plate made a mistake because dorsal eyes are present in most other species of Platevindex and because eyes can be difficult to see when dorsal papillae are retracted. However, it is confirmed here that dorsal eyes are not present in the type material of Platevindex latus. Labbé (1934: 234) identified two specimens (24/17 and 19/ 14 mm) from the Malabar coast (southwest India) collected by M. Dussumier as Oncis granulosa, but also indicated that the exterior aspect of his specimens was similar to that of Oncis lata from New Britain. However, Labbé also reported that the notum is granular with tubers that are not prominent, and that dorsal eyes are not very visible. The intestinal loops are also described as type II by Labbé, while they are of type III in Oncis lata. Due to the lack of dorsal papillae in the specimens Labbé examined, and the fact that Labbé’s description suggests that dorsal eyes may have simply been retracted, the specimens he examined are not considered to be Oncis lata. It is also worth noting that the specimens Labbé examined from western India are very distant from New Britain, Papua New Guinea, and that no observations of Oncis lata have been confirmed west of New Britain. Morphological evidence suggests that Platevindex latus is closely related to P. amboinae because both species lack penial hooks and dorsal eyes, which are present in all other species of Platevindex. They also are the only species of Platevindex with intestinal loops of type III., Published as part of Goulding, Tricia C., Bourke, Adam J., Comendador, Joseph, Khalil, Munawar, Quang, Ngo Xuan, Tan, Shau Hwai, Tan, Siong Kiat & Dayrat, Benoît, 2021, Systematic revision of Platevindex Baker, 1938 (Gastropoda: Euthyneura: Onchidiidae), pp. 1-133 in European Journal of Taxonomy 737 (1) on pages 116-121, DOI: 10.5852/ejt.2021.737.1259, http://zenodo.org/record/4594357, {"references":["Plate L. H. 1893. Studien ʾ ber opisthopneumone Lungenschnecken, II, Die Oncidiiden. Zoologische Jahrbucher, Abtheilung fur Anatomie und Ontogenie der Thiere 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 27 Sep. 2016].","Stantschinsky W. 1907. Zur Anatomie und Systematik der Gattung Onchidium. Zoologische Jahrbucher, Abteilung fur Systematik, Geographie und Biologie der Tiere 25: 353 - 402. https: // doi. org / 10.5962 / bhl. part. 11959","Dayrat B. 2009. Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa 2068: 1 - 26. https: // doi. org / 10.11646 / zootaxa. 2068.1.1","Hoffmann H. 1928. Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher (Jena) 55: 29 - 118.","Labbe A. 1934. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Martens E. von. 1897. S ʾ ss- und Brackwasser-Mollusken des Indischen Archipels. Zoologische Ergebnisse einer Reise in Niederlandisch Ost-Indien 4: 1 - 332. https: // doi. org / 10.5962 / bhl. title. 46994","Bretnall W. 1919. Onchidiidae from Australia and the south-western Pacific Islands. Records of the Australian Museum 12: 303 - 328. https: // doi. org / 10.3853 / j. 0067 - 1975.12.1919.888"]}

Platevindex applanatus (Simroth, 1920) comb. nov. Figs 36–45 Onchidium applanatum Simroth, 1920: 294, pl. 20, figs 40–42. Material examined Holotype INDONESIA • holotype (15/ 12 mm), by monotypy; Aru Inseln, Strand von Manumbai, Kobroor [Manumbai Beach, Kobroor Island, Aru Islands, Moluccas, Indonesia]; 13 Mar. 1908; H. Merton leg.; ZMB/Moll 104630. Notes on type material The notum of the holotype was cut open for the present study to check internal characters; all organs remain in the specimen. Other material INDONESIA – Ambon • 1 spec. (15/12 [2736] mm); Pulau Haruku; 03°36.520′ S, 128°25.068′ E; 11 Feb. 2014; station 127; dead log high on beach above rocky Sonneratia mangrove; UMIZ 00100 • 4 specs (22/15 [2754], 18/14 [2755], 18/14 [2757] and 15/12 [2750] mm); Passo; 03°37.080′ S, 128°16.068′ E; 13 Feb. 2014; station 129; logs on rocky beach with coral rubble; UMIZ 00101. – Seram • 2 specs (24/20 [2877] and 17/11 [2880] mm); Piru; 03°04.072′ S, 128°11.362′ E; 19 Feb. 2014; station 136; beach of palms and Acrostichum ferns behind Sonneratia mangrove; UMIZ 00090. – Kei Islands • 6 specs (21/14 [2892], 17/11 [3563], 16/10 [2893], 16/10 [2895], 13/6 [2894] and 12/9 [2900] mm); Un; 05°38.273′ S, 132°45.738′ E; 23 Feb. 2014; station 137; Bruguiera and Rhizophora mangrove with coral rubble and thin layer of mud; UMIZ 00102 • 1 spec. (15/9 [2904] mm); Un; 05°38.273′ S, 132°45.738′ E; 25 Feb. 2015; station 140; back of mangrove with rocks, mud, dead logs, and leaf litter; UMIZ 00103 • 1 spec. (5/4 [2925] mm); Fiditan; 05°35.957′ S, 132°45.112′ E; 28 Feb. 2014; station 144; rocks with mat of algae behind dense Rhizophora mangrove; UMIZ 00104. – Sulawesi • 1 spec. (17/11 [2160] mm); Bahoi; 01°43.355′ N, 125°01.232′ E; 10 Mar. 2013; station 85; sand, rocks and pieces of wood outside a mangrove; UMIZ 00083. MAURITIUS • 1 spec. (7/4 [3604] mm); Pointe Maurice; 20°15.447′ S, 57°47.670′ E; 8 Jun. 2014; station 174; Rhizophora mangrove with very dark mud, slug under piece of wood; MNHN-IM-2019-1392 • 1 spec. (9/7 [3152] mm); Mahebourg; 20°25.059′ S, 57°42.680′ E; 10 Jun. 2014; station 176; mangrove with dark brown mud, slugs on rotting petiole of palm frond; MNHN-IM-2019-1393 • 1 spec. (7/5 [3442] mm); same collection data as for preceding; MNHN-IM-2019-1394. PAPUA NEW GUINEA – Madang • 1 spec. (14/11 [5437] mm); South Dumduman Island; 05°00.2′ S, 145°47.6′E; 9 Nov.2012; MNHN expedition Papua Niugini leg.; station PM12; limestone rocky intertidal; MNHN-IM-2013-12493 • 1 spec. (16/16 [5424] mm); Hargun Island; 05°01.6′ S, 145°47.9′ E; 15, 20 Nov. 2012; MNHN expedition Papua Niugini leg.; station PM24; night tide; MNHN-IM-2013-14043 • 1 spec. (13/11 [5450] mm); same collection data as for preceding; MNHN-IM-2013-14051 • 1 spec. (18/15 [5420] mm); same collection data as for preceding; MNHN-IM-2013-13765 • 1 spec. (13/11 [5457] mm); Wonad Island; 05°08.1′ S, 145°49.3′ E; 27 Nov. 2012, 9 Dec. 2012; MNHN expedition Papua Niugini leg.; station PM41; sandy beach and intertidal rocks; MNHN-IM-2013-15867 • 1 spec. (13/10 [5462] mm); Tab Island; 05°10.2′ S, 145°50.4′ E; 28 Nov. 2012; MNHN expedition Papua Niugini leg.; station PM42; night tide, sandy beach and intertidal rocks; MNHN-IM-2013-15908. – New Ireland • 1 spec. (7/4 [6094] mm); Povalval, E coast of New Ireland; 02°41′ S, 150°57′ E; 11–13 Jun. 2014; MNHN expedition Kavieng 2014 leg.; station KM05; mixed hard platform and seagrass bed at outlet of rivulet; MNHN-IM-2013-53534 • 1 spec. (8/6 [6096] mm); Cape Jesehke, Manne Island; 02°43.1′ S, 150°37.8′ E; 15, 26 Jun. 2014; MNHN expedition Kavieng 2014 leg.; station KM32; Rhizophora mangrove; MNHN-IM-2013-54161 • 1 spec. (10/7 [6097] mm); same collection data as for preceding; MNHN-IM-2013-54163 • 1 spec. (8/6 [6098] mm); same collection data as for preceding; MNHN- IM-2013-54164. VANUATU • 1 spec. (12/11 [5491] mm); Santo Rose Point; 15°34.9′ S, 167°02.4′ E; 10 Sep. 2006; MNHN expedition Santo 2006 leg.; station VM02; intertidal, coral sand; MNHN-IM-2013-62402 • 1 spec. (9/8 [5493] mm); same collection data as for preceding; MNHN-IM-2013-62404. Description Color and morphology of live animals (Fig. 36) Live animals are not covered with mud and their natural color can be seen without washing. The notum is bumpy with prominent, distinctly-raised papillae (with or without dorsal eyes). Live animals may become nearly hemispherical when disturbed. The dorsal color is variable although it is typically brown with yellow longitudinal (irregular) lines. Slugs with an entirely dark brown notum or a light beige notum also occur. The hyponotum is light grey and almost translucent in small specimens. The margin of the hyponotum is frequently translucent with the brown color of the notum showing through. The foot is light yellow. Papillae with dorsal eyes are present. Their exact number is difficult to determine, as they are often retracted, but ranges approximately from 4 to 26, except in the case of very small specimens, in which as few as 2 dorsal eyes have been observed. Each papilla bears one dorsal eye. Dorsal eyes may be distributed across the notum or only present in the middle but are always absent on the margin (i.e., eyes are never Digestive system (Figs 1C, 37–40) Radulae measure up to 4.3 mm in length. Examples of radular formulae are presented in Table 5. Due to the high genetic divergence (in COI sequences) between populations of P. applanatus, radulae are figured from Indonesia, Mauritius and Papua New Guinea (Figs 37–39). Intestinal loops are of type I, with a transitional loop oriented between 1 and 2 o’clock (Figs 1C, 40 A–C). Reproductive system (Figs 41–44) In the posterior part of the reproductive system, the oviduct is wider than the deferent duct (up to twice as wide). Its distal section (distal to the spermatheca) is slightly longer than its proximal section (up to two or three times as wide) or equal to it in length. The deferent duct is longer than the oviduct, loosely attached to it, and varies from slightly convoluted with a few loose loops to tightly coiled with U-shaped loops (Fig. 41). The position of the female pore varies from being adjacent to the anus to 4 mm away from it in large specimens. The flexible, distal region of the penis with hooks measures approximately 1.5 to 3 mm in length. In eastern Indonesia, the distal region is 2 to 3 mm long, while in Mauritius and Papua New Guinea it is approximately 1.5 to 2 mm long. The penial hooks are large and can be seen inside the semi-transparent penis. They are usually 45 to 90 µm long (Figs 43, 44A), but between 20 to 60 µm in smaller specimens from Mauritius (Fig. 44 B–C). The insertion of the penial retractor muscle varies. It inserts at the posterior end of the visceral cavity in specimens from eastern Indonesia, except in a few specimens in which it inserts approximately ¾ down the length of the visceral cavity. It inserts approximately halfway to ¾ down the length of the visceral cavity in specimens from Papua New Guinea (and near the posterior end of the visceral cavity in one specimen). In Mauritius, it inserts at the posterior end of the visceral cavity in the largest specimen, and by the heart halfway down the visceral cavity in a smaller specimen. The length of the retractor muscle varies from much shorter than the penial sheath (1 / 5 to 1 / 3 of its length) to as long as the penial sheath. The deferent duct is not particularly long and is only loosely convoluted (Fig. 42). It may even be nearly straight in immature specimens (Fig. 42C). Distinctive diagnostic features (Table 4) Externally, Platevindex applanatus can be easily distinguished from P. martensi and P. aptei sp. nov. by the light yellow color of its foot. The presence of prominent dorsal papillae helps to distinguish P. applanatus from other species of Platevindex, except P. luteus, which is characterized by similar prominent dorsal papillae. The dorsal coloration of Platevindex applanatus is much more variable than in other species of Platevindex, and this variation prevents reliable separation from P. luteus. However, the dorsal notum of P. applanatus is frequently marked by bright yellowish-green markings or bands, which were very rarely observed in P. luteus. Individuals of P. applanatus also reach a smaller maximum size than individuals of P. martensi and P. amboinae, two species that are sympatric in eastern Indonesia, between the Halmahera Sea and the Banda Sea. However, animal sizes overlap between species and cannot be reliably used for identification. Internally, the intestinal loops of P. applanatus (type I) distinguish it from all other species of Platevindex. The only other species with intestinal loops of type I is P. luteus. However, the orientation of the transitional loop can be used to reliably distinguish P. applanatus (between 1 and 2 o’clock) from P. luteus (between 3 and 8 o’clock). Platevindex applanatus can also be distinguished from P. luteus based on reproductive anatomy. The deferent duct in the posterior reproductive system is more closely attached to the oviduct, longer and more highly coiled in P. applanatus than in P. luteus. The distal region of the oviduct (distal to the spermatheca) is also longer in P. applanatus than in P. luteus. Finally, the distal region of the penis with hooks is longer in P. applanatus (up to 3 mm) than in P. luteus (up to 1 mm). The insertion of the retractor muscle varies greatly within P. applanatus (it may insert at the posterior end of the visceral cavity or near the heart), so this character does not help to reliably distinguish it from P. luteus. Distribution (Fig. 10A) Indonesia: Ambon, Aru Islands (type locality), Kei Islands. Mauritius. Papua New Guinea: Madang and New Ireland. Vanuatu. All records are new, except for the type locality. Habitat (Fig. 45) Platevindex applanatus is primarily found in the high intertidal, including on limestone, on rocks covered with a thin layer of algae. In the Kei Islands, individuals were found on rocks at the upper margin of the intertidal near a mangrove. In Ambon, individuals were found on logs very high in the intertidal, including at one locality that was not near any mangrove. In mangroves, individuals were typically collected on dead logs or tree trunks. In Mauritius, it was found in mangroves, on pieces of wood and wet petioles of palm leaves. Platevindex applanatus is not found directly on mud. Remarks Onchidium applanatum was originally described from the Aru Islands. Fresh material was collected from the Kei Islands, very close to Aru. The holotype of Onchidium applanatum is small (15/ 12 mm) but its flattened shape, the presence of a rectal gland and no accessory penial gland all indicate that it is a Platevindex slug. The prominent papillae on its dorsal notum and its digestive system of type I are compatible with the species described here as well as P. luteus. However, the retractor muscle of the holotype of O. applanatum is very long and inserts near the posterior end of the visceral cavity, which is only compatible with the species described here (in P. luteus, the retractor muscle inserts near the heart). Therefore, Platevindex applanatus is applied to the species described here from the Kei Islands and Ambon. Hoffmann (1928: 84–85) and Labbé (1934: 225–226) considered that Onchidium applanatum and Onchidium tabularis Tapparone-Canefri, 1883 were both junior synonyms of Onchidium planatum Quoy & Gaimard, 1825. Onchidium planatum, originally described from Guam, may not even refer to an onchidiid based on the brief written description. Two pieces of a notum were located recently at the MNHN which are part of the type series of O. planatum (MNHN-IM-2000-33706). However, these are so poorly preserved that it is not possible to determine whether they were part of an onchidiid slug. Tapparone-Canefri’s (1883) description of O. tabularis from Wokam, Aru Islands, does not mention the internal anatomy, and the type specimens could not be located. As a result, both Onchidium planatum and Onchidium tabularis are considered here nomina dubia. Labbé’s (1934: 225–226) specimens identified as O. planatum from Guam, New Caledonia and Mauritius (as île de France) cannot belong to P. applanatus or any other species of Platevindex due to the presence of a penial gland.

Platevindex martensi (Plate, 1893) Figs 54–58 Oncis martensi Plate, 1893: 196–197, pl. 7, figs 7, 23a, pl. 10, fig. 50. Oncis inspectabilis Plate, 1893: 198–199. Syn. nov. Onchidium coriaceum – Semper 1880: 271–273 (in part only) [non Onchidium coriaceum Semper, 1880]. Oncis martensi – Stantschinsky 1907: 395. — Hoffmann 1928: 89. Oncis inspectabilis – Stantschinsky 1907: 395. Platevindex martensi – Dayrat 2009: 5. Platevindex mortoni – Zhang et al. 2017: fig. 1e (non Platevindex mortoni Britton, 1984). Material examined Holotype THAILAND • holotype (44/ 41 mm) by monotypy; Petshaburi, Gulf of Siam [Phetchaburi, Gulf of Thailand]; ZMB/Moll 8454. Holotype of Oncis inspectabilis MYANMAR • holotype (28/ 23 mm) by monotypy; Lampee, Birma [Lampi Island, Mergui Archipelago, southern Myanmar, Andaman Sea]; Anderson leg.; ZMB/Moll 38934. Notes on type material Oncis martensi. The holotype was previously dissected. Internal organs are mostly missing; only a few pieces of the female (posterior) reproductive system and digestive system remain. The penial complex and buccal mass are missing. Oncis inspectabilis. The holotype was previously dissected. Internal organs are mostly missing. The buccal mass remains, as well as pieces of the deferent duct, oviduct and spermatheca. Other material AUSTRALIA – Northern Territory • 4 specs (39/26 [1711], 25/20 [1709], 25/20 [1710] and 13/12 [1707] mm); Darwin, Elizabeth Road; 12°32.893′ S, 130°57.642′ E; 20 Aug. 2012; station 70; Ceriops and old logs in Rhizophora forest; NTM P.57611. BRUNEI • 1 spec. (43/29 [1040] mm); near Batu Marang; 04°59.131′ N, 115°01.820′ E; 29 Jul. 2011; station 34; old mangrove with tall Rhizophora trees with high roots and Thalassina mounds; BDMNH. INDONESIA – Sumatra • 1 spec. (52/19 [1767] mm); Pulau Sinaboi; 02°18.145′ N, 100°59.309′ E; 8 Oct. 2012; station 73; some small Avicennia and Rhizophora near shore; UMIZ 00107 • 1 spec. (22/13 [1776] mm); Dumai; 01°42.838′ N, 101°23.286′ E; 9 Oct. 2012; station 74; mangrove just behind abandoned buildings, high intertidal; UMIZ 00108 • 1 spec. (34/19 [1748] mm); Sungai Lubuk; 05°40.174′ S, 105°34.097′ E; 19 Oct. 2012; station 79; mounds of Thalassina, Rhizophora, dead logs in the high intertidal; UMIZ 00109. – Sulawesi • 2 specs (36/23 [2334] and 35/23 [2333] mm); Makassar City, Tallo; 05°06.117′ S, 119°26.777′ E; 21 Mar. 2013; station 92; small mangrove with outhouse in center; UMIZ 00111. MALAYSIA – Peninsular Malaysia • 1 spec. (30/18 [964] mm); Nibong Tebal, Pulau Burung; 05°12.488′ N, 100°25.564′ E; 11 Jul. 2011; station 17; Rhizophora mangrove with a few Sonneratia and soft mud; USMMC 00029 • 1 spec. (31/30 [934] mm); Balok; 03°53.219′ N, 103°21.978′ E; 14 Jul. 2011; station 19; Rhizophora mangrove with some Avicennia and mostly hard mud; USMMC 00030 • 2 specs (37/23 [no DNA] and 36/18 [no DNA] mm); Merbok; 05°39.035′ N, 100°25.782′ E; 18 Jul. 2011; station 21; deep Rhizophora forest with old, tall trees, hard mud, many small creeks and dead logs; USMMC 00031 • 1 spec. (39/21 [933] mm); Merbok; 05°40.143′ N, 100°26.178′ E; 19 Jul. 2011; station 22; mangrove of mostly Rhizophora, some Avicennia with soft mud near creek; USMMC 00077 • 1 spec. (37/15 [no DNA] mm); Langkawi, Tanjung Rhu; 06°25.317′ N, 99°50.106′ E; 15 Jul. 2011; station 26; open forest of Rhizophora, Sonneratia, Bruguiera with high mounds of mud around some trees; USMMC 00032 • 1 spec. (32/24 [930] mm); Kuala Sepatang; 04°50.434′ N, 100°38.176′ E; 19 Jul. 2011; station 27; old Rhizophora and Acrostichum ferns very high in tidal zone, near boardwalk; USMMC 00033. PHILIPPINES – Bohol • 2 specs (31/16 [3342] and 14/8 [3336] mm); Mabini; 09°51.532′ N, 124°31.685′ E; 17 Jul. 2014; station 194; narrow Rhizophora and Avicennia mangrove by the sea with fish ponds built on landward side, many dead logs; PNM 041250 • 4 specs (51/27 [3365], 34/22 [3364], 33/14 [3362] and 24/11 [3358] mm); Mabini; 09°51.402′ N, 124°30.982′ E; 18 Jul. 2014; station 195; narrow Rhizophora and Avicennia mangrove by the sea with fish ponds built on landward side, cement ditches between the mangrove patches and the ponds; PNM 041251. SINGAPORE • 1 spec. (31/20 [988] mm); Pasir Ris Park; 01°22.840′ N, 103°57.224′ E; 30 Mar. 2010; station 5; mud and dead logs in upper tidal; ZRC.MOL.10480 • 3 specs (40/22 [no DNA], 37/20 [no DNA] and 35/21 [987] mm); Lim Chu Kang; 01°26.785′ N, 103°42.531′ E; 5 Apr. 2010; station 9; piece of wood in Avicennia and Rhizophora mangrove; ZRC.MOL.10481. Description Color and morphology of live animals (Figs 54–55A) Live animals are not usually covered with mud, and their natural color is visible without washing. The dorsal notum is brown to dark brown or black, often mottled with two colors. The notum bears small elongated (longitudinal) ridges. The ventral color varies but the hyponotum is yellow, beige or yellow-orange, with distinct darker spots of variable size (small to large) and color (faintly tan to black). When those spots are large and dark enough, the hyponotum appears nearly black (which was most common in the Strait of Malacca). The hyponotum of juvenile specimens can be marked by fewer spots. In Malaysia, Singapore and Brunei, the edge of the hyponotum commonly is orange, which was also occasionally observed in other populations. The foot is distinctively orange. Papillae with dorsal eyes are present. Their exact number is variable (generally between 20 and 65). Each papilla bears one dorsal eye. Eyes are distributed across the notum and many eyes are found at the margin (i.e., eyes can be Digestive system (Figs 2 C–D, 55B–C, 56) Radulae measure up to 5 mm in length. Examples of radular formulae are presented in Table 5. The intestinal loops are of type II, with a transitional loop oriented between 6 and 9 o'clock. Reproductive system (Figs 55 D–F, 57) In the posterior part of the reproductive system, the oviduct is wider than the deferent duct (approximately up to twice as wide). Its distal section (distal to the spermatheca) is approximately up to twice as long as its proximal section. The deferent duct is longer than the oviduct, not attached to it, and highly coiled with tight, long, U-shaped loops. However, the deferent duct tends to be shorter in Malaysia and Northern Territory (Australia), and considerably longer in Brunei and the Philippines. The female pore is very close to the anus, between 0.5 mm and 2.5 mm apart. The distal, flexible region of the penis with hooks is approximately 2 to 2.5 mm long and approximately 170 µm wide. Penial hooks are relatively large, approximately 35 to 55 µm long (Fig. 57B), and can be seen inside the semi-transparent penis or when the penis is evaginated like the finger of a glove in the vestibule (Fig. 57A). The posterior retractor muscle of the penis inserts on the right side, within the third (posterior) quarter of the visceral cavity. The length of the retractor muscle varies from half the length of the penial sheath to slightly longer than the penial sheath. The deferent duct is highly convoluted (but is less convoluted in juvenile specimens). Distinctive diagnostic features (Table 4) Externally, the orange foot distinguishes Platevindex martensi from all other species of Platevindex. The small, elongated ridges on its dorsal notum are also present in P. aptei sp. nov., but the foot of P. aptei sp. nov. is black. The presence of many dorsal eyes right at the margin of the dorsal notum (within 2 mm from the edge) is only shared by P. martensi and P. aptei sp. nov. Internally, the long deferent duct with elongated loops in the anterior penial apparatus (which is not closely attached to the oviduct) differentiate P. martensi from other species of Platevindex. Also, the penial retractor muscle inserts between ½ to ¾ down the length of the visceral cavity in P. martensi while it inserts at the posterior end of the cavity in P. aptei sp. nov. Distribution (Fig. 10C) Australia: Northern Territory. Brunei. Indonesia: Sulawesi, Sumatra. Peninsular Malaysia. Myanmar: Andaman Sea (type locality of P. inspectabilis). Philippines: Bohol. Singapore. Thailand: Gulf of Thailand (type locality of P. martensi). All records are new, except for the type localities. Habitat (Fig. 58) Platevindex martensi is typically found in or near mangroves, on tree roots and trunks as well as dead logs. It usually lives in the high intertidal only reached by the highest tides (with Acrostichum ferns). It can also be found in cement ditches nearby a mangrove. One juvenile was found on coarse-grained sand in a mangrove forest in the Philippines, but Platevindex slugs normally are not found directly on mud or sand. Platevindex martensi is not found on rocky shores. Remarks All of the distinctive characters of Platevindex are present in the holotype of Oncis martensi, including a flattened and hard body, a narrow foot, a male opening to the right of the midline between the two eye tentacles and no accessory penial gland. In the original description of P. martensi, Plate (1893: 196) wrote that the holotype was collected from Singapore by professor von Martens. However, von Martens (1897: 128) later wrote that " Oncis martensi Plate was not found by me at Singapore, but at Petshaburi in the Gulf of Siam," which is in the north of the Gulf of Thailand. The label of the holotype at the Berlin Museum now reads " Siam, Petehabardi" (presumably a misspelling). Hoffmann (1928: 89) considered Petshaburi to be the type locality and even specified " Singapore, Plate, ex errore, nach Martens 1897." Also, note that the specific name appears as " martensi " in the text and in one figure caption (Plate 1893: 196, pl. 7, fig. 23a) but as " martensii " in the two other figure captions (Plate 1893: pl. 7, fig. 7, pl. 10, fig. 50). The posterior (female) reproductive system in the holotype of P. martensi is largely destroyed. The hermaphroditic gland is in pieces and disconnected from the hermaphroditic duct. A large part of the female gland mass is separated from the oviduct and the deferent duct. However, the long and convoluted deferent duct is intact and is only consistent with the species described here. Plate (1893: 197) also described the color of the live animal (based on field notes from von Martens) as having an intense yellow hyponotum with black marbling as well as a light gray-brown foot. A yellow hyponotum is only found in P. martensi and P. aptei sp. nov. The color of the foot is the external trait which can distinguish these two species, and Plate's description of "light gray-brown" is a closer match to the bright orange foot of P. martensi than the dark black foot of P. aptei sp. nov. The number of dorsal eyes he described (90) is higher than what we have observed in P. martensi, but we could not check this as the dorsal eyes have lost their pigment. Plate's (1893: 197) description of the dorsal eyes that "sit alone on the big warts" is consistent with this species, but his comment that "this rule does not apply without exception, because on about 12 warts there are 2 eye spots, so that one can speak in these cases of a group" is surprising. We have found no evidence that dorsal eyes occur in groups of two in this species; Plate's statement that dorsal eyes occurred in pairs suggests that his count of dorsal eyes is likely an overestimate. Plate's (1893: 198–199) original description of Platevindex inspectabilis from an island in southern Myanmar, in the Andaman Sea, mentioned the diagnostic characters of Platevindex. Plate indicated intestinal loops of type II, but this could not be verified because the intestine of the holotype was previously dissected. Plate's original description indicates a black-blue hyponotum (the color of the holotype has faded over time and could not be verified). Fresh specimens were not available from Myanmar, but many specimens were observed with a nearly solid black hyponotum (due to a high density of black spots) along the north-western coast of peninsular Malaysia. Despite a slight difference in the description of the hyponotum color, it can be determined that the holotype of P. inspectabilis belongs to the species described here due to the remains of its female (posterior) reproductive system. The length of the deferent duct adjacent to the oviduct is long and convoluted with elongated loops, which is indistinguishable from P. martensi (the deferent duct is similar in length in specimens of a similar size from Peninsular Malaysia). The length of the distal portion of the penis with hooks in P. inspectabilis (2 mm) also fits exactly the size range observed in P. martensi (2–2.5 mm). So, for all the reasons above, P. inspectabilis is considered here to be a junior synonym of P. martensi. Semper's (1882) original description of Onchidium coriaceum was based on syntypes that are part of at least two species (see our remarks on Platevindex coriaceus coriaceus). One paralectotype of O. coriaceum from Penang belongs to P. martensi. Indeed, its posterior (female) reproductive system is not compatible with P. coriaceus, P. tigrinus or P. luteus, but displays the diagnostic feature of P. martensi (the wide, long, highly-convoluted deferent duct adjacent to the oviduct). In addition, Semper rightly noted that dorsal eyes are present across the notum including on its margin, and dorsal eyes very close to the notum edge (P. martensi and P. aptei sp. nov. Zhang et al. (2017) recently re-described a species they identified as Platevindex mortoni based on specimens from Hong Kong, but P. mortoni is considered here a nomen dubium and their description is based on specimens that belong to at least two different species. One individual illustrated with a bright orange foot (Zhang et al. 2017: fig. 1e) is identified here as P. martensi. Plate (1893: 196–199) did not comment on the very close similarity between Platevindex inspectabilis and P. martensi in his original descriptions, but he compared P. inspectabilis to P. semperi, from the Philippines (Plate 1893: 199). This may be due to a similarity in their hyponotum color; the preserved hyponota of both O. inspectabilis and O. semperi were described by Plate as dark blue (though, now, decades later, the hyponotum is creamish in the type specimens of both species). However, P. inspectabilis and P. semperi are not regarded as synonyms because Plate's (1893: 193) description of the copulatory apparatus of P. semperi indicates that it is a junior synonym of P. coriaceus. Platevindex inspectabilis was also proposed as a synonym of Oncis stuxbergi by Hoffmann (1928: 88) and Labbé (1934: 235), but Vaginulus stuxbergi Westerlund, 1883 actually belongs to the genus Onchidium (Dayrat et al. 2016). We collected Platevindex martensi in Northern Territory, Australia, but did not find it in Queensland, Australia, though it cannot be excluded that we missed it there. An online photo (viewed at https://www.inaturalist.org/observations/14094815 on 30 Jul. 2018) from Maroochy, Mooloolaba, Queensland, shows a Platevindex slug with elongated dorsal ridges similar to those found in P. martensi and P. aptei sp. nov. Also, its description mentions that it is an "orange footed mangrove onch slug." Because no photograph of the ventral surface is available, the identification of that slug cannot be confirmed. Until this geographic record is confirmed by the examination of actual specimens, Queensland is not considered part of the geographic distribution for P. martensi., Published as part of Goulding, Tricia C., Bourke, Adam J., Comendador, Joseph, Khalil, Munawar, Quang, Ngo Xuan, Tan, Shau Hwai, Tan, Siong Kiat & Dayrat, Benoît, 2021, Systematic revision of Platevindex Baker, 1938 (Gastropoda: Euthyneura: Onchidiidae), pp. 1-133 in European Journal of Taxonomy 737 (1) on pages 96-103, DOI: 10.5852/ejt.2021.737.1259, http://zenodo.org/record/4594357, {"references":["Plate L. H. 1893. Studien ʾ ber opisthopneumone Lungenschnecken, II, Die Oncidiiden. Zoologische Jahrbucher, Abtheilung fur Anatomie und Ontogenie der Thiere 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 27 Sep. 2016].","Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880], 265 - 290 [1882], pls 19 - 20, 22 - 23 [1880], pl. 21 [1882], pls 24 - 27 [1885]. C. W. Kreidel, Wiesbaden, Germany. Available from https: // biodiversitylibrary. org / page / 32630046 [accessed 22 Dec. 2018].","Stantschinsky W. 1907. Zur Anatomie und Systematik der Gattung Onchidium. Zoologische Jahrbucher, Abteilung fur Systematik, Geographie und Biologie der Tiere 25: 353 - 402. https: // doi. org / 10.5962 / bhl. part. 11959","Hoffmann H. 1928. Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher (Jena) 55: 29 - 118.","Dayrat B. 2009. Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa 2068: 1 - 26. https: // doi. org / 10.11646 / zootaxa. 2068.1.1","Zhang K., Wang D., Shen H., Qian J., Guan H., Wu H. & Gao Y. 2017. Redescription of Platevindex mortoni (Gastropoda: Eupulmonata: Onchidiidae) from China. Molluscan Research 37: 72 - 78. https: // doi. org / 10.1080 / 13235818.2016.1223535","Britton K. M. 1984. The Onchidiacea (Gastropoda, Pulmonata) of Hong Kong with a worldwide review of the genera. Journal of Molluscan Studies 50: 179 - 191. https: // doi. org / 10.1093 / oxfordjournals. mollus. a 065863","Martens E. von. 1897. S ʾ ss- und Brackwasser-Mollusken des Indischen Archipels. Zoologische Ergebnisse einer Reise in Niederlandisch Ost-Indien 4: 1 - 332. https: // doi. org / 10.5962 / bhl. title. 46994","Labbe A. 1934. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Westerlund C. A. 1883. Noch einige von der Vega-Expedition gesammelte Mollusken. Nachrichtsblatt der deutschen malakozoologischen Gesellschaft 15: 164 - 166.","Dayrat B., Goulding T. C., Apte D., Bhave V., Comendador J., Ngo X. Q., Tan S. K. & Tan S. H. 2016. Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca: Gastropoda: Pulmonata: Onchidiidae). ZooKeys 636: 1 - 40. https: // doi. org / 10.3897 / zookeys. 636.8879"]}

Platevindex burnupi (Collinge, 1902) comb. nov. Figs 46–53 Onchidium burnupi Collinge, 1902: 17, figs 1–2. Onchidium burnupi – Collinge 1910: 171–172. — Connolly 1912: 224; 1939: 456. — Hoffmann 1928: 84. Material examined Lectotype SOUTH AFRICA • lectotype (here designated; 21/ 16 mm); Natal, Umlaas Lagoon [now the Umlazi River]; NHMUK 1905.4.12.33. Paralectotype SOUTH AFRICA • 1 paralectotype (18/ 12 mm); NHMUK 1905.4.12.34. Notes on type material The notum of the lectotype was cut open for the present study, with all internal organs remaining. The paralectotype was not dissected. Other material MADAGASCAR • 1 spec. (10/6 [3599] mm); Mangaoka area; 12°15.984′ S, 49°06.103′ E; 18 May 2014; station 160; mangrove of Avicennia and Rhizophora, many small trees in center of mangrove had been cut; MNHN-IM-2019-1396 • 1 spec. (16/9 [3150] mm); Madagascar, Ambaro Bay; 13°24.769′ S, 48°47.341′ E; 23 May 2014; Station 164; large, very dry mangrove of mostly Avicennia; MNHN- IM-2019-1398 • 1 spec. (14/9 [3151] mm);same collection data as for preceding; MNHN-IM-2019-1399 • 1 spec. (12/6 [3602] mm); same collection data as for preceding; MNHN-IM-2019-1397 • 1 spec. (16/10 [3603] mm); same collection data as for preceding; MNHN-IM-2019-1395. MOZAMBIQUE • 1 spec. (13/10 [729] mm); Mecufi, 50 km S of Pemba, Cabo Delgado Province [about 13° S]; 13 Jul. 2006; D.G. Reid leg.; on base of Ceriops bush in landward zone of mangrove belt, 30 cm above firm mud; NHMUK 20060274. SOUTH AFRICA • 1 spec. (32/11 [6146] mm); East Cape, Kwelera River estuary; 32°54.169′ S, 28°03.954′ E; 23 Jun. 2017; M. Cole leg.; mud amongst plants in supratidal fringe; ELM W04105 • 1 spec. (23/9 [6154] mm); same collection data as for preceding; ELM W04107 • 1 spec. (22/10 [6153] mm); same collection data as for preceding; ELM W04106 • 1 spec. (20/10 [6149] mm); same collection data as for preceding; ELM W04108 • 1 spec. (19/7 [6148] mm); same collection data as for preceding; ELM W04109. Description Color and morphology of live animals (Fig. 46) The dorsal notum of live animals can be covered with mud, in which case their color may be obscured until they are washed. The dorsal notum is brown with dark brown or black markings. The hyponotum is light blue-grey and the foot is yellow. Papillae with dorsal eyes are present. Their exact number is variable, approximately from 15 to 38 were observed in specimens from South Africa and between 12 and 20 were observed in specimens from Madagascar. Each papilla bears one dorsal eye. Eyes are distributed across the notum but are absent from the margin (i.e., eyes are never Digestive system (Figs 2G, 47–48B, 53) Radulae measure up to 3.3 mm in length. Examples of radular formulae are presented in Table 5. The intestinal loops are of type II, with a transitional loop oriented at approximately 7 o’clock (Figs 2G, 48A, 53). Reproductive system (Figs 49–51) In the posterior (female) reproductive system, the oviduct is short, wider than the deferent duct (approximately twice as wide). The length of its distal section (distal to the spermatheca) is shorter than or equal to that of its proximal section. The deferent duct is slightly longer than the oviduct, is only loosely attached to it and varies from loosely to tightly coiled (Fig. 49). The female pore is approximately 0.5 to 2 mm from the anus. The distal, flexible region of the penis with hooks is 1 to 1.5 mm long. Penial hooks are large, between 25 to 70 µm long (Fig. 51A), and can be seen inside the semi-transparent penis. The retractor muscle of the penis inserts on the right side at the posterior end of the visceral cavity (from the posterior end of the heart, up to the posterior end of the visceral cavity). The length of the retractor muscle varies from half the length of the penial sheath to approximately two times its length (Fig. 50B). The deferent duct is highly convoluted. Distinctive diagnostic features (Table 4) Platevindex burnupi is the only known species of Platevindex from the western Indian Ocean. It can be distinguished from P. martensi and P. aptei sp. nov. by its grey hyponotum and yellow foot, and from P. amboinae and P. latus by the presence of dorsal eyes. Platevindex burnupi is similar in appearance to P. luteus and P. applanatus, but lacks distinctly raised dorsal papillae. Its dorsal surface can even be smooth. It is difficult to distinguish P. burnupi from P. coriaceus and P. tigrinus due to their similar coloration and granular dorsal appearance. Although individuals of P. burnupi tend to be shorter than those of P. coriaceus and P. tigrinus, animal sizes overlap and cannot be used for identification. Internally, the intestinal loops of type II differentiate P. burnupi from P. amboinae, P. latus, P. applanatus and some specimens (with intestinal loops of type I) of P. luteus. The reproductive system can be used to distinguish P.burnupi from all other species of Platevindex. The deferent duct in the posterior reproductive system is loosely attached to the oviduct in P. burnupi, which distinguishes it from P. coriaceus and P. tigrinus (deferent duct closely attached to the oviduct). The distal region of the penis with penial hooks is also much shorter in P. burnupi (1–1.2 mm) than in P. coriaceus (2–8 mm). Platevindex burnupi is very difficult to differentiate from P. luteus internally. They differ only slightly with respect to the insertion of the penial retractor muscle (near the heart in P. luteus and in the last posterior quarter of the visceral cavity in P. burnupi). DNA sequences are the most reliable way to distinguish Platevindex burnupi and P. luteus, which are more than 10.5% divergent based on COI sequences. Distribution (Fig. 10A) Madagascar, Mozambique and South Africa (type locality and newly-collected material). Habitat (Figs 45 A–B, 52C–D) Like other species of Platevindex, P. burnupi is found on mangrove trees but, unlike other species, it may also be found on mud. Specimens in Madagascar were found high in the intertidal on moist mud not saturated in water, and one specimen was found on a piece of wood. A specimen from Mozambique was collected on the base of a Ceriops tree, 30 cm above ground. All specimens in South Africa were on mud, in the supra-tidal zone of a salt marsh, a few meters away from the river. Remarks Onchidium burnupi must be transferred to Platevindex because of the following combination of characters in the lectotype: flattened body, rectal gland present and no penial gland. The type locality (Umlaas Lagoon, Natal, South Africa) was visited twice by our team and several times by experts from the Natal Museum (Dai Herbert, pers. com.), but no onchidiid species were ever found. This is very likely due to the fact that the Umlaas Lagoon has been developed and natural vegetation destroyed. However, onchidiids similar to the lectotype of O. burnupi were recently collected by Mary Cole and Philippe Bouchet in the estuary of the Kwelera River, East Cape, South Africa (approximately 400 km south of the type locality). As of today, no other live population of P. burnupi is known in South Africa (assuming that there is no live population at the type locality). Note that several authors have mentioned the existence of Onchidium burnupi in South Africa but exclusively based on the original description, i.e., without providing new specimens or records (Connolly 1912, 1939; Collinge 1910; Hoffmann 1928). Platevindex burnupi is known from two localities in South Africa, three localities in Madagascar and one locality in Mozambique. High genetic divergences between populations from Madagascar and Mozambique versus South Africa (5.4–6.0%) as well as the fact that they are consistently recovered as reciprocally-monophyletic units (Figs 4–8) suggest that there could be more than one species. However, there is not enough evidence to justify the description of a new species in Madagascar. The anatomy of populations from South Africa and Madagascar are similar, and little is known about intraspecific variation across its distribution. The genetic divergences between Madagascar and East Africa (Mozambique and South Africa) could be the result of the large geographic distance between localities. However, there are some noticeable differences between the populations in the two regions. The most noticeable difference between regions is animal length: individuals collected from South Africa (up to 32 mm) are significantly larger than those from Madagascar (up to 16 mm) and Mozambique (13 mm). However, intermediate sizes may be found when additional populations are discovered, or this could be due to a difference in climate. The deferent duct in the posterior (female) reproductive system is slightly longer in specimens from Madagascar than in specimens from South Africa (even though animal size is larger in South Africa), but this could also be the result of population structure (this trait is known to vary between individuals). In addition, the insertion of the retractor muscle is more posterior in specimens from Madagascar than in South Africa. Finally, Madagascan individuals were found in a different habitat (mangrove) than in South Africa (salt marsh). Salt marshes in Madagascar were not visited for this study and may need to be explored in the future.

A key is provided to help identify the nine species of Platevindex. Because species cannot always be distinguished externally, the key also includes internal characters. 1. Dorsal eyes absent, penial hooks absent, intestinal loops of type III..........................................2 – Dorsal eyes present, penial hooks present (in mature specimens), intestinal loops of type I or II, but never of type III...........................................................................................................................3 2. Dorsal surface bears large, thorny papillae...................................................... P. latus (Plate, 1893) – Dorsal surface bears only small papillae................................................ P. amboinae (Plate, 1893) 3. Hyponotum yellow with dark spots, foot orange or black, dorsal surface bears low longitudinal ridges, dorsal eyes can be very close (P. martensi (Plate, 1893) – Foot black................................................................................. P. aptei Goulding & Dayrat sp. nov. 5. Notum bears distinctly-raised papillae (with or without eyes), slug frequently semi-hemispherical (especially when disturbed)...............................................................................................................6 – Notum granular, with papillae with dorsal eyes but no distinctly-raised, prominent papillae, slugs normally remain flattened (even when disturbed)............................................................................7 6. No bright yellow longitudinal areas on dorsal notum, intestinal loops of types I or II with a transitional loop oriented between 3 and 8 o’clock, retractor muscle of penis inserts near heart................................................................................................................................ P. luteus (Semper, 1880) – Bright yellow longitudinal areas present on dorsal notum, intestinal loops of type I with a transitional loop oriented between 1 and 2 o’clock, retractor muscle of penis inserts near heart or at posterior end of visceral cavity................................................... P. applanatus (Simroth, 1920) 7. Distal portion of oviduct (distal to spermatheca) shorter than proximal portion (from female gland mass to spermatheca)............................................................................... P. burnupi (Collinge, 1902) – Distal portion of oviduct (distal to spermatheca) much longer than proximal portion (from female gland mass to spermatheca)...............................................................................................................8 8. Retractor muscle of penis inserts near heart, distal region of penis (with hooks) less than 1.5 mm long, deferent duct attached to oviduct (in posterior part of reproductive system) and almost straight..................................................................................................... P. tigrinus (Stoliczka, 1869) – Retractor muscle of penis inserts near posterior end of visceral cavity, distal region of penis (with hooks) more than 2 mm long, deferent duct attached to oviduct (in posterior part of reproductive system) and highly coiled...................................................................... P. coriaceus (Semper, 1880), Published as part of Goulding, Tricia C., Bourke, Adam J., Comendador, Joseph, Khalil, Munawar, Quang, Ngo Xuan, Tan, Shau Hwai, Tan, Siong Kiat & Dayrat, Benoît, 2021, Systematic revision of Platevindex Baker, 1938 (Gastropoda: Euthyneura: Onchidiidae), pp. 1-133 in European Journal of Taxonomy 737 (1) on pages 124-125, DOI: 10.5852/ejt.2021.737.1259, http://zenodo.org/record/4594357, {"references":["Plate L. H. 1893. Studien ʾ ber opisthopneumone Lungenschnecken, II, Die Oncidiiden. Zoologische Jahrbucher, Abtheilung fur Anatomie und Ontogenie der Thiere 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 27 Sep. 2016].","Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880], 265 - 290 [1882], pls 19 - 20, 22 - 23 [1880], pl. 21 [1882], pls 24 - 27 [1885]. C. W. Kreidel, Wiesbaden, Germany. Available from https: // biodiversitylibrary. org / page / 32630046 [accessed 22 Dec. 2018].","Simroth H. 1920. Uber einige Nacktschnecken vom Malayischen Archipel von Lombok an ostwarts bis zu den Gesellschafts-Inseln. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 35: 259 - 306. Available from https: // biodiversitylibrary. org / page / 48256899 [accessed 22 Dec. 2018].","Collinge W. E. 1902. Description of a new species of Onchidium from South Africa. The Journal of Malacology 9: 17. Available from https: // biodiversitylibrary. org / page / 28220831 [accessed 20 Jan. 2020].","Stoliczka F. 1869. The malacology of lower Bengal and the adjoining provinces. Journal of the Asiatic Society of Bengal 38: 86 - 111. Available from https: // www. biodiversitylibrary. org / item / 128669 page / 366 / mode / 1 up [accessed 27 Sep. 2016]"]}

Platevindex aptei Goulding & Dayrat sp. nov. urn:lsid:zoobank.org:act: 25DECF9A-226F-40A8-BC49-99815E6B2B9D Figs 59–63 Etymology Platevindex aptei sp. nov. is named for Deepak Apte, a great naturalist and the Executive Director of the Bombay Natural History Society, Mumbai, India. Deepak Apte provided great help in the organization of our fieldwork in India as well as with molecular lab work at the National Centre for Cell Science in Pune. We would not have been able to explore the mangroves of India without his assistance. Material examined Holotype INDIA • holotype (45/20 [1112] mm); Andaman Islands, Shantipur, Kadamtala; 12°19.844′ N, 92°46.377′ E; 12 Jan. 2011; station 58, mangrove creek, open forest, lots of dead logs and trees; BNHS 3-1112. Other material INDIA – Andaman Islands • 1 spec. (35/20 [1092] mm); Shamkund, near Rangat; 12°29.448′ N, 92°50.620′ E; 11 Jan. 2011; station 57; ditches by road to the mangroves with high trees down to the mud on side of river; BNHS 8-1092 • 1 spec. (35/20 [1093] mm); same collection data as for preceding; BNHS 8-1093 • 3 specs (55/35 [#1], 50/35 [#2] and 25/18 [#3] mm); same collection data as for preceding; BNHS 8 • 1 spec. (25/20 [1111] mm); Shantipur, Kadamtala; 12°19.844′ N, 92°46.377′ E; 12 Jan. 2011; station 58; mangrove creek, open forest, lots of dead logs and trees; BNHS 3-1111 • 1 spec. (38/22 [1121] mm); Shoal Bay, by Bamboo Flat; 11°47.531′ N, 92°42.576′ E; 13 Jan. 2011; station 59; ditches and mud along the road; BNHS 14-1121. MALAYSIA – Peninsular Malaysia • 1 spec. (28/17 [no DNA] mm); Penang; 05°23.782′ N, 100°11.469′ E; 8 Jul. 2011; station 12; open Avicennia mangrove with many dead logs; USMMC 00035 • 2 specs (50/39 [#1] and 35/23 [932] mm); Merbok; 05°39.035′ N, 100°25.782′ E; 14 Jul. 2011; station 21; deep Rhizophora forest with old, tall trees, hard mud, many small creeks and dead logs; USMMC 00036 • 1 spec. (31/24 [917] mm); Matang; 04°50.154′ N, 100°36.868′ E; 20 Jul. 2011; station 29; old Rhizophora mangrove with hard mud and open space between trees; USMMC 00037 • 3 specs (42/25 [5967], 37/21 [5968] and 35/22 [5955] mm); Matang; 04°50.217′ N, 100°36.826′ E; 26 Jul. 2016; station 256; old Rhizophora mangrove with hard mud and open space between trees; USMMC 00078. Description Color and morphology of live animals (Fig. 59) Live animals are not usually covered with mud, and their natural color is usually visible without washing. The dorsal notum is brown, sometimes with darker markings. The notum bears low, elongated (longitudinal) ridges. The foot is black (Malaysia) or dark brown (India). The background of the hyponotum is bright yellow (Malaysia) to light yellow or beige (India) with a varying number of spots that range from light brown (India) to dark brown or black (Malaysia). Spots tend to be more concentrated around the margin of the hyponotum, but their density is highly variable (from only around the margin to the entire hyponotum). Exceptionally, the hyponotum can be homogenously dark brown with only a small yellow band around the foot. Small or juvenile specimens tend to have fewer or no spots on the hyponotum. Papillae with dorsal eyes are present. Their exact number is variable (between 35 and 50). Each papilla bears one dorsal eye. The dorsal eyes are distributed across the notum, with numerous eyes at the margin of the notum (i.e., many eyes are Digestive system (Figs 2F, 60, 61 A–B) Radulae measure up to 6.4 mm long. Examples of radular formulae are presented in Table 5. The intestinal loops are of type II, with a transitional loop oriented between 7 and 9 o’clock (Figs 2F, 61 A–B). Reproductive system (Figs 61C, 62) In the posterior part of the reproductive system, the oviduct is wider than the deferent duct (up to twice as wide). Its distal section (distal to the spermatheca) is slightly longer than its proximal section and is sharply bent (U-shaped). The deferent duct is slightly longer than the oviduct, not attached to it, and loosely to highly convoluted (Fig. 61C). The penial sheath is very thick but the penis inside is extremely thin. The vestibule is cylindrical and attached to the anterior, dorsal wall of the visceral cavity by many short muscle fibers. The distal, flexible region of the penis with hooks is approximately 2.5 to 5 mm long and is very narrow, approximately 80 µm wide. Penial hooks are large, approximately 30 to 40 µm long, and can be seen inside the semi-transparent penis. The retractor muscle of the penis inserts at the posterior end of the visceral cavity, near the rectum. The retractor muscle varies from much shorter than the penial sheath (one-fifth its length) to approximately as long as the penial sheath. In the penial complex, the deferent duct is convoluted in small loops (Fig. 62D). Distinctive diagnostic features (Table 4) Externally, Platevindex aptei sp. nov. can be easily distinguished from all other known species of Platevindex by its strikingly distinctive black or dark brown foot. The bright yellow or beige hyponotum distinguishes it from most other species of Platevindex, but this also occurs in P. martensi. Low, elongated (longitudinal) ridges on the dorsal notum are diagnostic of P. aptei sp. nov. as well as P. martensi. Internally, the thick penial sheath with a very narrow penis is a distinctive characteristic of P. aptei sp. nov., and the flexible region of the penis bearing spines is longer in P. aptei sp. nov. (2.5–5 mm) than in P. martensi (2–2.5 mm long). Distribution (Fig. 10C) India: Andaman Islands. Malaysia: Peninsular Malaysia. Habitat (Fig. 63) Platevindex aptei sp. nov. is found in mangroves, typically on large, dead logs, as well as on tree trunks and roots, and cement ditches adjacent to mangroves, but is not found directly on mud. It is usually found in the high intertidal. It does not live on rocky shores. Remarks Platevindex aptei sp. nov. may also be present in Singapore, although it was not found there during our recent visit. Many onchidiid species present in the Bay of Bengal and Peninsular Malaysia are also present in Singapore, such as Platevindex coriaceus, P. tigrinus, P. martensi, Peronina tenera (Goulding et al. 2018c), Onchidium typhae (Dayrat et al. 2016), Melayonchis siongkiati and M. eloisae (Dayrat et al. 2017). However, there are other instances of onchidiid species which have not recently been found in Singapore even though they should be there based on their known geographic distribution, such as Onchidium stuxbergi (Dayrat et al. 2016) and Melayonchis aileenae Dayrat & Goulding, 2017 (Dayrat et al. 2017).A photo of a slug erroneously identified as Onchidium griseum, but which actually illustrates Platevindex aptei sp. nov., was found online, posted on the website WildSingapore.com with photos of P. martensi. The locality listed with the photo online is Sungei Buloh Wetland Reserve, Singapore, suggesting that P. aptei sp. nov. is present there. However, if P. aptei sp. nov. is present in Singapore, it may be at low abundance.

Platevindex tigrinus (Stoliczka, 1869) comb. nov. Figs 26–30 Onchidium tigrinum Stoliczka, 1869: 105–107, pl. 15, fig. 2. Platevindex mortoni – Sun et al. 2014: 63. — Zhang et al. 2017: fig. 1 [non Platevindex mortoni Britton, 1984]. Material examined Neotype (here designated) INDIA • neotype (28/18 [1066] mm); Sundarbans, Bali Island; 22°04.387′ N, 88°41.828′ E; 6 Jan. 2011; station 50; soft mud by the sea with a few mangrove trees and dead logs; BNHS 18-1066. Notes on type material The designation of a neotype is needed in order to clarify the application of the name Onchidium tigrinum (ICZN Article 75.3.1). The characters that differentiate P. tigrinus from other species of Platevindex are mentioned below in a section on ‘Distinctive diagnostic features’ (ICZN Article 75.3.2). The neotype is preserved separately and will be easily recognized (ICZN Article 75.3.3). The syntypes could not be located after an exhaustive search of museum collections (Dayrat 2009) (ICZN Article 75.3.4). What is known of the former syntypes, from the original description and illustrations, is consistent with the neotype (ICZN Article 75.3.5). The type locality is the banks of the Mutlah River at Port Canning [Matla River, Ganges Delta, India] and the neotype was collected as nearly as practicable from the original type locality in West Bengal (ICZN Article 75.3.6), and it is already the property of a scientific institution, the Bombay Natural History Society, in Mumbai, India (ICZN Article 75.3.7). The neotype was collected on soft mud by the sea with a few mangrove trees and dead logs. The designation of a neotype is exceptionally needed in order to make sure that the application of the name Onchidium tigrinum remains unambiguous (see Remarks below). Other material BRUNEI • 2 specs (29/18 [1033] and 15/14 [1032] mm); Sungai; 04°53.756′ N, 114°59.496′ E; 26 Jul. 2011; station 31; very large, tall Rhizophora mangrove with soft mud; BDMNH • 1 spec. (23/16 [1030] mm); Pulau Pyatan, Teluk Brunei; 04°55.246′ N, 115°02.764′ E; 27 Jul. 2011; station 32; open mangrove with a few sparse old trees and large old logs, by the river; BDMNH. INDIA – West Bengal • 1 spec. (13/10 [1065] mm); same collection data as for neotype; BNHS 18-1065 • 1 spec. (22/15 [#1] mm); same collection data as for neotype; BNHS 18. – Andaman Islands • 1 spec. (40/30 [1094] mm); Shamkund, near Rangat; 12°29.448′ N, 92°50.620′ E; 11 Jan. 2011; station 57; by a large river, deep mangrove with tall trees, small creeks and old muddy logs, next to a road and a small cemented bridge across creek; BNHS 2-1094 • 2 specs (35/22 [#1] and 24/15 [1114] mm); Shantipur, Kadamtala; 02°19.844′ N, 92°46.377′ E; 12 Jan. 2011; station 58; open area with hard mud and many old logs, next to a mangrove; BNHS 12-1114 • 1 spec. (25/22 [1123] mm); Shoal Bay, by Bamboo Flat; 11°47.531′ N, 92°42.576′ E; 13 Jan. 2011; station 59; open mangrove with hard mud, old logs, next to a road and a small cemented bridge across creek; BNHS 1-1123. – Maharashtra • 1 spec. (25/16 [1140] mm); Khandra mangrove; 19°03.876′ N, 72°49.296′ E; 18 Dec. 2011; station 43; very small Avicennia trees in mud; BNHS 35-1140 • 1 spec. (36/26 [1160] mm); Vatad; 17°15.791′ N, 73°17.623′ E; 23 Dec. 2011; station 46; Avicennia mangroves by field with deep and very watery mud; BNHS 104-1160 • 1 spec. (29/16 [1178] mm); Areware mangrove; 17°04.404′ N, 73°17.747′ E; 24 Dec. 2011; station 47; mangrove of Avicennia and a few small Rhizophora with soft mud and areas with pooled water; BNHS 33-1178. MALAYSIA – Peninsular Malaysia • 3 specs (23/17 [953], 21/18 [955] and 14/12 [956] mm); Matang, Crocodile River off Kuala Septang; 04°49.521′ N, 100°37.630′ E; 10 Jul. 2011; station 16; mangrove with tall Rhizophora; USMMC 00022 • 2 specs (27/18 [939] and 26/14 [5522] mm); Merbok; 05°39.035′ N, 100°25.782′ E; 18 Jul. 2011; station 21; deep Rhizophora forest with old, tall trees, hard mud, many small creeks and dead logs; USMMC 00023 • 1 spec. (14/13 [936] mm); Langkawi Island, Tanjung Rhu; 06°25.771′ N, 99°49.436′ E; 13 Jul. 2011; station 23; young Rhizophora, Sonneratia and Avicennia in a dense forest with small creeks; USMMC 00024. SINGAPORE • 1 spec. (21/17 [992] mm); Lim Chu Kang; 01°26.785′ N, 103°42.531′ E; 2 Apr. 2010; station 7; open mangrove forest with tall trees and soft mud by river, ending on sun-exposed mudflat; ZRC.MOL.10472 • 1 spec. (18/17 [993] mm); Semakao Island; 01°12.083′ N, 103°45.585′ E; 3 Apr. 2010; station 8; landfill island with newly planted mangrove, very dense; ZRC.MOL.10473 • 1 spec. (19/13 [994] mm); Lim Chu Kang; 01°26.785′ N, 103°42.531′ E; 5 Apr. 2010; station 9; open mangrove forest with tall trees and soft mud by river, ending on sun-exposed mudflat; ZRC.MOL.10474. Description Color and morphology of live animals (Fig. 26) The dorsal surface is bumpy, not smooth, and typically brown with dark brown or yellow-brown markings. The hyponotum color varies from bluish grey to light grey. The edge of the hyponotum may be slightly lighter, but there is no prominent light-colored line around the entire edge. The foot color varies from dark blue-grey to light yellow. The number of papillae with dorsal eyes is variable (generally between 25 and 50). Dorsal eyes are distributed across the notum but are absent from its margin (i.e., eyes are never Digestive system (Figs 27A, 28) Radulae measure up to 5 mm in length. Examples of radular formulae are presented in Table 5. The intestinal loops are of type II, with transitional loops oriented between 6 and 9 o’clock (Fig. 27A). Reproductive system (Figs 27 B–C, 29) The oviduct is much wider than the deferent duct (approximately up to three times). Its distal section (distal to the spermatheca) is up to three times as long as its proximal section (Fig. 27B). The deferent duct is closely attached to the oviduct and almost straight (with only loose turns). The distal, flexible, hook-bearing section of the penis is 1 to 1.5 mm long. The penial hooks are approximately 60 to 100 µm long, and can be seen inside the semi-transparent penis. In mature specimens, the retractor muscle inserts on the right side of the visceral cavity near the heart. The retractor muscle is from one quarter as long as the penial sheath to equal to it in length (Fig 27C). The deferent duct is not highly convoluted, with only a few loops (and is even less convoluted in immature specimens). Distinctive diagnostic features (Table 4) Externally, the yellow foot of Platevindex tigrinus clearly distinguishes it from P. martensi (orange foot) and P. aptei sp. nov. (black foot). Platevindex tigrinus is very similar externally to P. amboinae, except that the notum of P. tigrinus bears many dorsal eyes which are absent in P. amboinae. Platevindex tigrinus can be distinguished from P. latus by its granular dorsal surface and the lack of large, thorny dorsal papillae. Its granular dorsal surface also helps to distinguish it from P. luteus and P. applanatus, which bear prominent dorsal papillae when disturbed, although it is still possible to confuse these three species. Platevindex tigrinus cannot be distinguished externally from P. coriaceus, which has been found in many of the same sites, except in India (where P. coriaceus has not been found so far). Internally, the intestinal loops clearly distinguish P. tigrinus (type II) from P. applanatus (type I). Some individuals of P. luteus are characterized by intestinal loops of type II and cannot be distinguished from P. tigrinus based only on the digestive system. The reproductive system can also be used to differentiate P. tigrinus from P. coriaceus, P. luteus and P. burnupi. In P. tigrinus, the retractor muscle for the penis inserts near the heart on the right side of the visceral cavity (i.e., in the posterior half or third of the cavity) while it inserts at the posterior end of the cavity in P. coriaceus. In P. tigrinus the deferent duct is closely attached to the oviduct (in the posterior reproductive system), while it is only loosely attached to it in P. luteus and P. burnupi. This trait also differs slightly between P. tigrinus and P. coriaceus: the deferent duct, which is closely attached to the oviduct in both species, is almost straight in P. tigrinus and highly-convoluted, with tight, U-shaped turns in P. coriaceus. Distribution (Fig. 10B) Brunei. India: Andaman Islands, Maharashtra and West Bengal (type locality and fresh specimens newly collected). Peninsular Malaysia. Singapore. Southern China (specimens misidentified as Platevindex mortoni in Sun et al. 2014 and Zhang et al. 2017). All records are new, except for the type locality. Habitat (Fig. 30) Platevindex tigrinus is found in mangroves, on tree trunks and roots and dead logs, but is not found directly on mud. Those logs and trees may be in silty mud saturated with water or in the mid-intertidal. It does not live on rocky shores. Platevindex tigrinus is common across most of its geographic range. It is one of the most abundant onchidiid species in the mangroves of India. Remarks Stoliczka’s illustration of the external appearance of O. tigrinum clearly shows a Platevindex slug (Stoliczka 1869: fig. 2). In his description of O. tigrinum, Stoliczka emphasized the flattened shape of the slug, the narrow foot and the hardened notum, which are all diagnostic of Platevindex. Other aspects of the original description are also in agreement with Platevindex: a granular dorsal surface, a foot from one third to one fourth the total width of the body, dorsal eyes on papillae of the notum and a male opening above the right oral lobe. Therefore, O. tigrinum is transferred to Platevindex. Stoliczka’s description of the color of the ventral surface is as follows: “Young specimens have the mantle below uniform light bluish with very numerous and white dots; large ones have occasionally a number of dark green or rusty, more or less confluent spots along the lateral margins, and the general colour is pale. The foot (...) is of a uniform dark bluish grey colour.” (Stoliczka 1869: 106). The color of Stoliczka’s young specimens perfectly matches the species described here and the color of the large ones is also within the observed color variation. The species treated here is the only one that we found at the type locality of O. tigrinum with a blue-grey ventral surface, strongly suggesting that the name O. tigrinum applies to the species described here. Also, Stoliczka mentioned that, at the type locality, O. tigrinum was common and found crawling on old wood, which is in complete agreement with our observations in the field, including at the type locality. There is, however, a problem with Stoliczka’s original description of O. tigrinum. Indeed, Stoliczka (1869: 107) stated that the “internal vas deferens is about 5 inches, and its supplementary albuminous string [Stoliczka’s term for the accessory penial gland] about 8 inches long.” An accessory penial gland is not present in any species of Platevindex and this strongly suggests that a species from another genus was part of the type material, although it cannot be excluded that he made a mistake. Thus, the designation of a neotype is needed because it allows us to ensure that, in the future, O. tigrinum will always apply to the species described here. The designation of a neotype is far more preferable to a lectotype designation based on an illustration or description. Indeed, even though the species described here is the only Platevindex we found at the type locality of O. tigrinum, it cannot be excluded that other species, especially P. luteus, will be found there in the future. Because P. luteus and P. tigrinus are hardly distinguishable externally, it is possible that Stoliczka also examined some specimens of P. luteus. For all the reasons above, the neotype designated here efficiently clarifies the application of O. tigrinum. In his remarks on Onchidium coriaceum, Semper (1882: 273) addressed the similarity between the species he described and Stoliczka’s description of Onchidium tigrinum. Semper pointed out that the only difference between the two descriptions is the presence of an accessory penial gland in O. tigrinum, but doubted that one was actually present in Stoliczka’s specimens of O. tigrinum. Semper considered O. tigrinum to be a synonym of O. coriaceum (although with a question mark), even though he was not able to properly compare the anatomy of the two species, and even though, strictly speaking, O. tigrinum had priority over O. coriaceum. Platevindex tigrinus is shown here to be genetically and anatomically distinct from P. coriaceus. Hoffmann (1928: 77) noted Semper’s comments on the similarity between Onchidium tigrinum and Oncis stuxbergi, but did not provide additional comments on the species or add new localities. Hoffmann’s indication that the species was from “Port Canning (Penang, Malayische Halbinsel)” [Penang, Peninsular Malaysia] appears to be a mistake for Stoliczka’s locality of Port Canning in West Bengal, India. Labbé (1934: 223) repeated Hoffmann’s erroneous record but did not provide new information about the species. The type material of Platevindex mortoni, a species originally described by Britton (1984) from Hong Kong, includes a holotype by original designation (NHMUK 1982288) and three paratypes (NHMUK 1982289/1,2 and NHMUK 1982289/3). The holotype (18/ 16 mm) is missing both the male and female reproductive parts, which were not described in detail by Britton. Also, its digestive system is largely destroyed (the intestinal loops cannot be observed) even though the radula remains. The two largest paratypes (22/18 and 15/ 15 mm) are empty of all internal organs. All organs remain in the smallest (9/ 9 mm) paratype but it is not fully mature (the posterior, female reproductive parts are only partly developed). The intestinal loops of the smallest paratype are clearly of type II. Britton did not describe the color of the ventral surface (foot and hyponotum) of live animals. He only mentioned that the preserved holotype and two preserved paratypes (NHMUK 1982289/1,2) were brown with a darker mantle rim, while the third paratype (NHMUK 1982289/3) was grey with darker mottling. However, the dorsal color is useless for identifying species of Platevindex and a brown dorsal surface with a darker mantle rim (color of the holotype) could apply to any species. Britton’s description of the type of intestinal loops is also problematic. He described intestinal loops of type I in the holotype, of type II in what he called the “grey paratype ” (NHMUK 1982289/3), which is the largest paratype, and intermediate between types I and II in the smallest paratype. Intestinal loops of type II are clearly present in the smallest paratype (the only type specimen with remaining intestinal loops) which Britton called the “smaller brown paratype.” There are three possible explanations for that. First, Britton correctly described the intestinal loops of the holotype of P. mortoni (the only specimen with a name-bearing function) and the name P. mortoni cannot apply to P. tigrinus or P. coriaceus, two species with intestinal loops of type II and which are known to be present in Hong Kong (see below). However, the name P. mortoni could apply to P. luteus, a species with intestinal loops of type I, but which is not known from Hong Kong (although it is known from the Philippines and Vietnam, among other places). Second, it is also possible (and quite likely) that Britton simply made a mistake in identifying the type of the intestinal loops in the holotype of P. mortoni because he also misidentified the intestinal type in another onchidiid that he called Paraoncidium reevesii (J.E. Gray, 1850) (see Goulding et al. 2018b). If Britton misidentified the intestinal loops in the holotype of P. mortoni, the description would be compatible with P. tigrinus. Third, it is also possible that the original description of P. mortoni was based on specimens from two different species (one with a type I and one with a type II), even though, strictly speaking, only the holotype is the name-bearer. Because Britton’s description of P. mortoni is confusing and since critical characters cannot be checked in the type material, P. mortoni is regarded as a nomen dubium. It does apply to a species of Platevindex, but which one cannot be confidently determined. DNA sequences of onchidiids from China published by Sun et al. (2014) show that there are several species of Platevindex in China and at least two in Hong Kong. For unclear reasons, Sun et al. applied the name P. mortoni to all Chinese onchidiids with a bluish-grey hyponotum and foot. By comparing their DNA sequences with ours, we have determined that the sequenced specimens they called P. mortoni belong to P. tigrinus and P. coriaceus. The specimens called P. mortoni from southern China, east of Hainan (including Hong Kong), are here referred to P. tigrinus, while a specimen collected from southern China west of Hainan belongs to P. coriaceus. Zhang et al. (2017) recently re-described a species they identified as Platevindex mortoni based on specimens from Hong Kong. This description did not address the inconsistency in the original description regarding the intestinal loops and appears to be based on multiple species of Platevindex. Despite the fact that COI sequences from Sun et al. (2014) showed that several species of this genus are present in China, including two in Hong Kong, Zhang et al. did not discuss how the species they re-described was different from other sympatric species of Platevindex. Photographs of live specimens by Zhang et al. clearly show that there are two different kinds of ventral coloration. The individual with a blue-grey foot and hyponotum (Zhang et al. 2017: fig. 1c) was either P. tigrinus or P. coriaceus (both could potentially be present in Hong Kong), and the individual with a bright orange foot (Zhang et al. 2017: fig. 1E) is identified here as P. martensi., Published as part of Goulding, Tricia C., Bourke, Adam J., Comendador, Joseph, Khalil, Munawar, Quang, Ngo Xuan, Tan, Shau Hwai, Tan, Siong Kiat & Dayrat, Benoît, 2021, Systematic revision of Platevindex Baker, 1938 (Gastropoda: Euthyneura: Onchidiidae), pp. 1-133 in European Journal of Taxonomy 737 (1) on pages 60-68, DOI: 10.5852/ejt.2021.737.1259, http://zenodo.org/record/4594357, {"references":["Stoliczka F. 1869. The malacology of lower Bengal and the adjoining provinces. Journal of the Asiatic Society of Bengal 38: 86 - 111. Available from https: // www. biodiversitylibrary. org / item / 128669 page / 366 / mode / 1 up [accessed 27 Sep. 2016]","Sun B., Chen C., Shen H., Zhang K., Zhou N. & Qian J. 2014. Species diversity of Onchidiidae (Eupulmonata: Heterobranchia) on the mainland of China based on molecular data. Molluscan Research 34: 62 - 70. https: // doi. org / 10.1080 / 13235818.2013.868860","Zhang K., Wang D., Shen H., Qian J., Guan H., Wu H. & Gao Y. 2017. Redescription of Platevindex mortoni (Gastropoda: Eupulmonata: Onchidiidae) from China. Molluscan Research 37: 72 - 78. https: // doi. org / 10.1080 / 13235818.2016.1223535","Britton K. M. 1984. The Onchidiacea (Gastropoda, Pulmonata) of Hong Kong with a worldwide review of the genera. Journal of Molluscan Studies 50: 179 - 191. https: // doi. org / 10.1093 / oxfordjournals. mollus. a 065863","Dayrat B. 2009. Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa 2068: 1 - 26. https: // doi. org / 10.11646 / zootaxa. 2068.1.1","Hoffmann H. 1928. Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher (Jena) 55: 29 - 118.","Labbe A. 1934. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Gray J. E. 1850. Figures of Molluscous Animals Selected from Various Authors. Etched for the Use of Students by M. E. Gray. Volume IV. Longman, Brown, Green and Longmans, London. https: // doi. org / 10.5962 / bhl. title. 4772","Goulding T. C., Khalil M., Tan S. H. & Dayrat B. 2018 b. Integrative taxonomy of a new and highly-diverse genus of onchidiid slugs from the Coral Triangle (Gastropoda: Pulmonata: Onchidiidae). ZooKeys 763: 1 - 111. https: // doi. org / 10.3897 / zookeys. 763.21252"]}

Genus Platevindex Baker, 1938 Type species Onchidium coriaceum Semper, 1880, by original designation (Baker 1938: 88). Diagnosis Body dorso-ventrally flattened. Notum hard. No dorsal gills. Dorsal eyes present (in most species) or absent (only in two species). Dorsal eyes occur individually, never in groups. Eyes at the tip of short ocular tentacles. Foot narrow, approximately ¼ to ⅓ of total width. Pneumostome median, on ventral hyponotum. Intestinal loops of types I, II or III. Accessory penial gland absent. Male opening below two ocular tentacles, almost centered, but slightly to right side (in dorsal view). Rectal gland present. Penis composed of two regions: rigid proximal region and flexible distal region. Penial hooks in distal region present (in most species) or absent. Gender The gender is masculine (ICZN Article 30.1.1). The generic name Platevindex was formed from the family name of the German zoologist Dr. Ludwig H. Plate (1862–1937), professor at Jena, who described several onchidiid species. No gender was specified in Baker’s (1938) original publication of the generic name Platevindex. However, Baker (1938: 88) changed the ending of the specific name coriacea (combined with the generic name Oncis Plate, 1893) to coriaceus, indicating that he considered Platevindex to be of masculine gender. Also, the Latin word ‘ vindex ’, meaning ‘protector’ or ‘champion’, is masculine. As a result, the ending of all specific names transferred to Platevindex must become masculine (e.g., Onchidium luteum becomes Platevindex luteus). Distinctive diagnostic features Platevindex slugs can easily be identified in the field by their dorso-ventrally flattened body, firm notum and very narrow foot (one third of the total width or less when the animal is not active). However, no combination of internal characters is unique to Platevindex. Slugs with a rectal gland and no accessory penial glands are also found in Melayonchis and Onchidina. Also, among Platevindex, Melayonchis and Onchidina slugs, intestinal loops of type I are found only in Platevindex, but intestinal loops of type II are found in all three genera and intestinal loops of type III are found in both Platevindex and Melayonchis. The lateral radular teeth of Platevindex are characterized by a slight protuberance on their inner lateral margin (e.g., see arrows on Figs 18B, 34C, 48C, 57C, 66C). This kind of radular protuberance is unusual among onchidiids. Apart from in Platevindex, it has been observed only in Marmaronchis, in which the protuberance is also slight (Dayrat et al. 2018), and in Melayonchis, where it is much more conspicuous and sharp (Dayrat et al. 2019c). Remarks Several of the species that belong to Platevindex were classified in Plate’s genus Oncis. Baker (1938) established the generic name Platevindex as a replacement name for Oncis Plate, 1893, which he treated as a junior homonym of Oncis Herrmannsen, 1847. However, Oncis Herrmannsen, 1847 was a mere nomenclator entry (“ Oncis - vid. Onchis ”) which referred to Onchis Férussac, 1822, an available generic name, and which Herrmannsen treated as a full entry. Because Oncis was not treated as the valid name of a taxon by Herrmannsen (1847), it is not an available name under ICZN Article 11.5. Regardless of the nomenclatural status of Oncis Herrmannsen, 1847, the generic name Oncis Plate, 1893 is not available because it is a junior objective synonym of Onchis Férussac, 1822. Indeed, under ICZN Article 33.2.1, one reason for a change in the original spelling of a name to be interpreted as “demonstrably intentional” is “when two or more names in the same work are treated in a similar way.” In his revision of the onchidiids, Plate (1893) changed the original spelling of Onchidium to Oncidium, that of Onchidina to Oncidina, and that of Onchidella Gray, 1850 to Oncidiella. It is thus obvious that Plate (1893) considered that Oncis was a “demonstrably intentional” spelling change from Onchis. The generic name Oncis Plate, 1893 is thus an emendation of Onchis Férussac, 1822, but it is an unjustified emendation because Plate’s (1893) correction was not made in accordance with Article 32.5. As an unjustified emendation, Oncis Plate, 1893 is a junior objective synonym of Onchis Férussac, 1822 and it enters in homonymy (Article 33.2.3). The fact that Plate (1893: 164) claimed that Oncis was a new generic name does not change the fact that, according to the Code, it is treated as an unjustified emendation of Onchis Férussac, 1822. Interestingly, several authors already treated Oncis Plate, 1893 as a junior objective synonym of Onchis Férussac, 1822. For instance, according to Woodward (1894: 57), Oncis Plate, 1893 is a “ nom. preocc. Onchis (i.e., Oncis), Fér., = Peronia, Blainv. ”. Also, Woodward (1894: 57) designated Oncis coriacea as the type species of Oncis. Regardless, being a junior objective synonym of Onchis Férussac, 1822, Oncis Plate, 1893 is objectively invalid. Oncis Plate, 1893 actually refers to the taxon of which the type species is Onchidium peronii Cuvier, 1804 (i.e., the type species of Onchis Férussac, 1822), and thus refers to the genus Peronia Fleming, 1822, not Platevindex (Dayrat et al. 2020). As a result, the valid generic name for the genus revised here is Platevindex, which Baker (1938) rightly established as a new generic name to refer to the taxon erroneously named Oncis by Plate (1893), even though the justification provided by Baker was not completely appropriate. Finally, Baker (1938: 87) correctly pointed out that the generic name Semperella Labbé, 1934 was a junior homonym of Semperella Gray, 1868 (Porifera). Baker (1938: 87) considered Semperella Labbé as a subjective synonym of Platevindex but provided no explanation; Semperella Labbé was later replaced by Semperoncis Starobogatov, 1976, which refers to a genus of terrestrial onchidiids (Dayrat 2009, 2010). Distribution Platevindex is broadly distributed in the Indo-West Pacific from the eastern coast of South Africa (~ 32° South) to New Ireland, Papua New Guinea and eastern Australia in the Pacific (~ 21° South). It has been documented up to 33° North in southern Japan (Takagi et al. 2019). The known geographic range of each species is illustrated in Fig. 10., Published as part of Goulding, Tricia C., Bourke, Adam J., Comendador, Joseph, Khalil, Munawar, Quang, Ngo Xuan, Tan, Shau Hwai, Tan, Siong Kiat & Dayrat, Benoît, 2021, Systematic revision of Platevindex Baker, 1938 (Gastropoda: Euthyneura: Onchidiidae), pp. 1-133 in European Journal of Taxonomy 737 (1) on pages 35-36, DOI: 10.5852/ejt.2021.737.1259, http://zenodo.org/record/4594357, {"references":["Baker H. B. 1938. Nomenclature of Onchidiidae. The Nautilus 51: 85 - 88. https: // doi. org / 10.5962 / bhl. part. 10914","Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880], 265 - 290 [1882], pls 19 - 20, 22 - 23 [1880], pl. 21 [1882], pls 24 - 27 [1885]. C. W. Kreidel, Wiesbaden, Germany. Available from https: // biodiversitylibrary. org / page / 32630046 [accessed 22 Dec. 2018].","Plate L. H. 1893. Studien ʾ ber opisthopneumone Lungenschnecken, II, Die Oncidiiden. Zoologische Jahrbucher, Abtheilung fur Anatomie und Ontogenie der Thiere 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 27 Sep. 2016].","Dayrat B., Goulding T. C., Khalil M., Lozouet P. & Tan S. H. 2018. Systematic revision one clade at a time: A new genus of onchidiid slugs from the Indo-West Pacific (Gastropoda: Euthyneura: Pulmonata). Raffles Bulletin of Zoology 66: 814 - 837. Available from https: // lkcnhm. nus. edu. sg / app / uploads / 2018 / 01 / 66 rbz 814 - 837. pdf [accessed 20 Jan. 2020].","Dayrat B., Goulding T. C., Bourke B., Khalil M. & Tan S. H. 2019 c. New species and new records of Melayonchis slugs (Gastropoda: Euthyneura: Pulmonata: Onchidiidae). Raffles Bulletin of Zoology 67: 557 - 585. Available from https: // lkcnhm. nus. edu. sg / app / uploads / 2019 / 01 / RBZ- 2019 - 0043. pdf [accessed 20 Jan. 2020].","Gray J. E. 1850. Figures of Molluscous Animals Selected from Various Authors. Etched for the Use of Students by M. E. Gray. Volume IV. Longman, Brown, Green and Longmans, London. https: // doi. org / 10.5962 / bhl. title. 4772","Woodward B. B. 1894. Mollusca. Zoological Record 30: 57.","Fleming J. 1822. Mollusca. In: Napier M. (ed.) Supplement to the Fourth, Fifth and Sixth Editions of the Encyclopaedia Britannica. Volume 5: 567 - 584. Edinburgh.","Dayrat B., Goulding T. C., Apte D., Aslam S., Bourke A. J., Comendador J., Khalil M., Ngo X. Q., Tan S. K. & Tan S. H. 2020. Systematic revision of Peronia Fleming, 1822 (Gastropoda, Euthyneura, Pulmonata, Onchidiidae). ZooKeys 972: 1 - 224. https: // doi. org / 10.3897 / zookeys. 972.52853","Labbe A. 1934. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Starobogatov Y. I. 1976. Composition and taxonomic position of marine pulmonate mollusks. Soviet Journal of Marine Biology 4: 206 - 212.","Dayrat B. 2009. Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa 2068: 1 - 26. https: // doi. org / 10.11646 / zootaxa. 2068.1.1","Dayrat B. 2010. Anatomical re-description of the terrestrial onchidiid slug Semperoncis montanta (Plate, 1893). Malacologia 52 (1): 1 - 20. https: // doi. org / 10.4002 / 040.052.0101","Takagi M., Takao Y., Mizuno K. & Ieyama H. 2019. Genetic diversity of Onchidiidae in Japan. Fauna Ryukyuana 49: 23 - 37."]}

Melayonchis siongkiati Dayrat & Goulding in Dayrat et al., 2017 (Figs. 17–20) Melayonchis siongkiati Dayrat & Goulding in Dayrat et al., 2017: 1871–1878, figs. 9–15. Type locality. Singapore, Mandai River, 01°26.237ʹN, 103° 45.730ʹE, 2 April 2010, station 6, following the river from the railroad towards the sea, open mangrove forest with tall trees and soft mud, ending on sun-exposed mudflat outside the mangrove with very soft mud. Type material. Holotype, by original designation, 32/20 [1002] mm (ZRC.MOL.6501). Additional material examined. Australia, Northern Territory, upper Darwin Harbour, Elisabeth River, upstream Bennetts Creek, 12°35.26740ʹ, 131°01.31160ʹ, 7 September 2016, 1 specimen 33/22 [5875] mm, station 265, at midtide level, on bank of Rhizophora -dominated tidal creek, deeply buried within moist woody debris and decaying stumps (NTM P.59483); Australia, Northern Territory, upper Darwin Harbour, Elisabeth River, upstream Bennetts Creek, 12°35.26740ʹ, 131°01.31160ʹ, 7 September 2016, 1 specimen 35/20 [5877] mm, station 265, at mid-tide level, on bank of Rhizophora -dominated tidal creek, deeply buried within moist woody debris and decaying stumps (NTM P.59484); Australia, Northern Territory, upper Darwin Harbour, Elisabeth River, upstream Bennetts Creek, 12°35.26740ʹ, 131°01.31160ʹ, 7 September 2016, 1 specimen 28/20 [5878] mm, station 265, at mid-tide level, on bank of Rhizophora - dominated tidal creek, deeply buried within moist woody debris and decaying stumps (NTM P.59485). Distribution (Fig. 6). Australia, Northern Territory (new record). Other records are in Brunei Darussalam, Peninsular Malaysia, Singapore (type locality), and Vietnam (Dayrat et al., 2017: 1872). Habitat. In the Northern Territory, M. siongkiati was found at one site deeply buried within moist woody debris and decaying stumps, on the bank of a tidal creek, in a Rhizophora -dominated forest. In the rest of its distribution, M. siongkiati usually lives in old forests where it is found on tree trunks and roots as well as logs, though it can occasionally be found on cemented walls of ditches or bridges near mangroves (Dayrat et al., 2017: 1873). Abundance. Melayonchis siongkiati is extremely rare in the Northern Territory. Only a few specimens at one site were found in years of mangrove exploration by Adam Bourke. In the rest of its distribution, M. siongkiati is abundant only in Brunei and a large population was found at one site in Malaysia (Dayrat et al., 2017: 1873). Live animals (Fig. 17). The beige background of the notum is irregularly mottled with darker areas, both light and dark brown. The colour of the hyponotum varies between light to dark gray and is marked by a significantly lighter ring at the margin. The foot is pale orange. When the animal crawls undisturbed, the brown ocular tentacles are short and extend for only a few millimeters beyond the notum margin, and the head is small and remains covered by the dorsal notum. The body is elongated, oval, usually not flattened, though animals may seem flattened when crawling. The dorsal notum is not particularly thick. Its surface, when the animal is undisturbed, is not smooth. Dorsal gills and large papillae are absent, but small conical papillae are present. About 15 of those papillae bear a black dorsal eye. A very slightly larger, central papilla bears three black dorsal eyes. In addition, the notum is finely granular. When disturbed, the animal can coil up, and occasionally even form a complete ball. Also, when disturbed, the dorsal notum immediately secretes an abundant oily and shiny mucus. Finally, the dorsal notum of disturbed animals tends to be smooth (instead of finely granular). Live animals are from 28 to 35 mm long. Digestive system (Figs. 18, 19, Table 4). Examples of radular formulae are presented in Table 4. The length of the rachidian teeth is approximately 30 µm, significantly less than the lateral teeth. The length of the hook of the lateral teeth is approximately 60 µm, excluding the first few (about 5) innermost and outermost lateral teeth which are significantly smaller. The inner lateral aspect of the hook of the lateral teeth is not straight. It is marked by a strong protuberance placed over the preceding adjacent tooth. The tip of the hook is similar across the half row, although it tends to be slightly more pointed in the innermost and slightly more round in the outermost teeth. The intestinal loops are of type III, with a transitional loop oriented at approximately 4 o’clock. A rectal gland is present. Reproductive system (Fig. 18B). The receptaculum seminis (caecum) is spherical ovate. The spermatheca is ovate and connects to the oviduct through a very short duct. The oviduct and the deferent duct are narrow and straight. A vaginal gland is absent. Copulatory apparatus (Figs. 18C, 20). The male anterior organs consist of the penial complex (penial papilla, penial sheath, deferent duct, and retractor muscle) and the accessory penial gland (flagellum and hollow spine). The penial complex and the accessory penial gland share the same vestibule and male opening. The flagellum of the penial gland is coiled. Distally, it ends in a hard, hollow spine. The hollow spine is narrow, elongated, and slightly curved. It measures about 60 μm in diameter at its conical base and narrows down to 15 to 20 μm distally, for a length that varies from 0.6 to 0.7 mm. The hollow spine opens into the proximal region of the vestibule. The penial sheath protecting the penial papilla is straight and short (approximately 1 mm long) and joins distally the accessory penial gland in the vestibule. The total length from the retractor muscle attachment (proximal end of the penial sheath) to the opening of the vestibule is about 4 mm. The penial papilla consists of a short tube, slightly conical at its base and a slightly enlarged tip. Its length ranges between 0.4 and 0.5 mm. Its diameter is approximately 130 to 150 μm at the base, 150 μm at the tip, and 60 μm in between. There are no penial hooks. The retractor muscle is longer or shorter than the penial sheath and inserts at about half the length of the floor of the visceral cavity. The deferent duct is highly convoluted with many loops. Remarks. The description of the individuals from the Northern Territory matches perfectly the original description of M. siongkiati from the Strait of Malacca and the South China Sea (Dayrat et al., 2017). Most especially, they share the most distinctive trait of the species, i.e., an abundant secretion of oily mucus when animals are disturbed, which is convenient to identify M. siongkiati in the field. Individuals can also coil up into a ball, but not as systematically and completely as M. eloisae or M. eberlyi. The dorsal colour of live animals, which is quite variable, is harder to use for identification. When crawling animals are observed without being disturbed, they could easily be confused with other species, including species from other genera (e.g., Platevindex, Wallaconchis). The only differences observed between individuals from the Northern Territory and the rest of the species are minor and can easily be explained by geographic distance and the fact that all three Australian specimens come from the same population (Table 3): the pedal sole is orange in Australian individuals and grey in the rest of the species; the penial papilla is slightly shorter in Australian individuals (0.4 to 0.5 mm long) compared to the rest of the species (0.5 to 1 mm long)., Published as part of Dayrat, Benoît, Goulding, Tricia C., Bourke, Adam J., Khalil, Munawar & Tan, Shau Hwai, 2019, New species and new records of Melayonchis slugs (Gastropoda: Euthyneura: Pulmonata: Onchidiidae), pp. 557-585 in Raffles Bulletin of Zoology 67 on pages 578-581, DOI: 10.26107/RBZ-2019-0043, http://zenodo.org/record/5343617

Paromoionchis goslineri Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: E375A628-4AE6-4E10-B424-D4BBF58F8941 Figs 45–51 Etymology Paromoionchis goslineri gen. et sp. nov. is dedicated to Dr. Terry Gosliner, Senior Curator at the California Academy of Sciences, San Francisco, California, USA, who has been exploring the marine life of the Batangas region for many years, where this new species was found, and, more importantly, for years ago providing the first author with a great post-doctoral opportunity to focus on alpha-taxonomy. Material examined Holotype PHILIPPINES • holotype (25/15 [3233] mm); Luzon, Calantagan, Batangas; 13°51.264´N, 120°37.383´E; 8 Jul. 2014; station 185; next to village, impacted narrow mangrove forest of Avicennia by the shore; PNM 0 41271. Other material INDONESIA – Sulawesi • 1 spec. (20/14 [2210] mm); Bahoi; 01°43.355´N, 125°01.232´E; 12 Mar. 2013; station 88; sand, small rocks and pieces of wood outside narrow coastal mangrove; UMIZ 0 0 161 • 1 spec. (18/10 [2241] mm); Sondaken; 01°21.777´N, 124°32.594´E; 13 Mar. 2013; station 89; mostly Rhizophora, with sand, small rocks and pieces of wood outside narrow coastal mangrove; UMIZ 0 0 153. – Bali • 3 spec. (22/15 [3060], 22/15 [3066] and 27/20 [3068] mm); Denpasar; 08°46.126´S, 115°10.803´E; 2 Apr. 2014; station 154; large mangrove by road, with shallow mud; UMIZ 0 0 154 • 4 spec. (20/12 [3072], 17/10 [3074], 22/14 [3078] and 24/14 [3079] mm); Gilimanuk; 08°10.259´S, 114°26.606´E; 3 Apr. 2014; station 155; from high intertidal with water pools and many mounds up to shore with sand and rocks; UMIZ 0 0 155 • 2 spec. (22/10 [3118] and 37/20 [3120] mm); Gilimanuk; 08°10.156´S, 114°26.652´E; 4 Apr. 2014; station 156; muddy mangrove with Rhizophora and Avicennia trees; UMIZ 0 0 156. – Timor • 2 spec. (12/7 [5890] and 15/7 [5891] mm); Oesapa; 10°08.732´S, 123°38.096´E; 11 Jul. 2016; station 250; sandy part of mangrove, with Sonneratia and Avicennia; UMIZ 0 0 157. – Halmahera • 2 spec. (24/16 [5072] and 32/23 [5073] mm); Dodinga; 00°51.348´N, 127°38.504´E; 9 Mar. 2015; station 206; back of mangrove, high intertidal, with ferns and mounds; UMIZ 0 0 158 • 1 spec. (35/22 [5145] mm); Gamkonora; 01°26.911´N, 127°31.625´E; 21 Mar. 2015; station 219; mostly Rhizophora, with some sandy and open muddy areas; UMIZ 0 0 159. – Ambon • 1 spec. (12/7 [3555] mm); Wai; 03°34.652´S, 128°19.526´E; 15 Feb. 2014; station 132; narrow band of old Avicennia trees on sandy mud, with old logs; UMIZ 0 0 160. PHILIPPINES – Luzon • 2 spec. (22/15 [3221] and 20/16 [6049] mm); Calantagan, Batangas; 13°53.278´N, 120°37.124´E; 8 Jul. 2014; station 184; narrow forest on the shore, with Avicennia and young Rhizophora; PNM 0 41272 • 1 spec. (28/20 [3232] mm); same data as for holotype; PNM 0 41273. Color and morphology of live animals (Figs 45–46) Live animals are most often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is gray-brown, mottled with darker and lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be lighter (pale yellow or white). The foot and the hyponotum are dark or light gray. The color of both the foot and the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are gray-brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). The tip of dorsal papillae is usually white or pale yellow, but not always (in any case generally covered with mud). Digestive system (Figs 47A, 48A, 49–50) Radulae measure up to 2.6 mm (unit #1) and 2.2 mm (unit #2) in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 47 B–C, 48B–C) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle). An accessory penial gland is absent. The penial sheath is narrow and elongated. In unit #1, the retractor muscle is very short (much shorter than the penial sheath), inserting on the body wall near the nervous system, or vestigial (its distal end being free in the visceral cavity, with no clear insertion). In unit #2, the retractor muscle is long (as long as the penial sheath), inserting near the heart. The deferent duct is also highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, smooth (no hooks) and hollow tube of approximately 200 μm in diameter. Distinctive diagnostic features Externally, Paromoionchis goslineri gen. et sp. nov. cannot be distinguished from other species of Paromoionchis gen. nov. The ventral side (foot and hyponotum) is gray, i.e., never yellow or orange. Unfortunately, a gray ventral side can occasionally be found in all other species of the genus, so the use of that color trait is not fully reliable for identification. However, the internal anatomy of P. goslineri gen. et sp. nov. (no accessory penial gland, thin penis with no hooks) is very distinctive and can be used for a fully reliable identification. The only other species of Paromoionchis gen. nov. without an accessory penial gland, P. penangensis gen. et sp. nov., differs greatly from P. goslineri gen. et sp. nov. anatomically because its penis is very large. Units #1 and #2 of P. goslineri gen. et sp. nov. differ slightly with respect to the penial retractor: it is short and thin, inserting near the nervous system, or even vestigial in unit #1, while it is as long as the penial sheath, inserting near the heart in unit #2. However, given that only four specimens could be dissected in unit #1, it is very possible that intermediates may be found in the future, especially considering that units #1 and #2 are widely distant geographically. Distribution (Fig. 6) Philippines (unit #1): Luzon (type locality). Indonesia (unit #2): Ambon, Bali, Halmahera, Sulawesi and Timor. Habitat (Fig. 51) Paromoionchis goslineri gen. et sp. nov. unit #1 is found on mud, in Avicennia forests near the shore and is rare (only four specimens are known from two stations). Unit #2 is found on soft and hard mud, in mangroves or in open areas near mangroves and is rare (except in Bali, where several specimens were found at a few stations).

Paromoionchis Dayrat & Goulding gen. nov. urn:lsid:zoobank.org:act: 4506A7F2-CC0B-4F23-8F5E-4DE2AA42B61F Type species Onchidium tumidum Semper, 1880, designated here. Diagnosis Body not flattened. No dorsal gills. Dorsal eyes present on notum. Retractable, central papilla (usually with four dorsal eyes) present, often raised above dorsal surface. Eyes at tip of short ocular tentacles. Male opening below right ocular tentacle and to its left. Foot wide. Pneumostome median, on ventral hyponotum. Intestinal loops of type II. Rectal gland absent. Accessory penial gland present or absent. When present, accessory penial gland with muscular sac. Penis with or without hooks. Differential diagnosis No external diagnostic feature unambiguously distinguishes Paromoionchis gen. nov. from all other genera (which is not surprising because many onchidiid species from different genera are very similar externally). However, Paromoionchis gen. nov. is characterized by a unique combination of internal and external characters: no dorsal gills, male opening below and to the left of the right eye tentacle, no rectal gland and intestinal loops of type II (see Labb�� 1934a: 177, fig. 3, for a comparison of digestive types). According to our data, any onchidiid slug with this combination of characters must belong to a species of Paromoionchis gen. nov. Etymology The name Paromoionchis is a combination of par��moios (����������o��oς), which means ��similar�� in Greek (because members look very similar externally) and onchis, a word derived from the Greek onchos (��� ���������ς) and one of the early names used to refer to onchidiid slugs. Gender Masculine, the gender of onchis (ICZN Art. 30.1.1), a word derived from the masculine Greek word ��� ���������ς (onchos), which means ��mass�� or ��tumor.�� As a result (ICZN Art. 31.2), the ending of the specific name tumidum (a Latin adjective) must be changed from neuter (because Onchidium is a name of neuter gender) to masculine (tumidus). Distribution The new genus described here is distributed from the western coast of India in the west, all the way to the subtropical waters of Japan (~33�� N), Papua New Guinea and the subtropical waters of southeastern Australia (~32�� S) in the east (Fig. 6). We did not find Paromoionchis gen. nov. in South Africa, Madagascar or Mauritius, but it is possible that it is present in areas east of Papua New Guinea, such as Fiji and New Caledonia, where we did not collect. Habitat The five known species of Paromoionchis gen. nov. primarily live on mud, in or next to mangroves, which explains why three species have just been discovered now, because the mangroves of South- East Asia have been very poorly explored. Occasionally, these slugs can also be found in or on muddy logs, coral rubble, sandy mud or even sand with very little mud in it. Paromoionchis tumidus, which is widespread and very common, can be found in nearly all these habitats, even though the mud surface remains where it is most commonly found, like all other species of the genus. Because members of Paromoionchis gen. nov. prefer the mud surface, live animals are often covered with mud. Remarks A new generic name is needed because no existing name applies to the clade described here. Our remarks are based on the examination of all the type specimens available, especially those of the type species of all genera, the careful analyses of all the original descriptions (especially when no type specimens were available), and our ongoing taxonomic revision of each genus of the family. Three existing generic names are junior synonyms of Onchidella J.E. Gray, 1850, which is not found in the tropical Indo-West Pacific and is characterized by a completely different anatomy (Dayrat 2009; Dayrat et al. 2011b). Seven generic names apply to the clade including all the onchidiid slugs with dorsal gills, i.e., Peronia Fleming, 1822 (Dayrat 2009). Labella Starobogatov, 1976 is a junior synonym of Onchidium Buchannan, 1800, which applies to a distinct clade including three species (Dayrat et al. 2016). Paraoncidium Labb��, 1934 is a junior synonym of Onchidina Semper, 1882, which applies to a distinct monotypic genus from southeastern Australia (Dayrat & Goulding 2017). Peronina Plate, 1893 applies to a clade including slugs characterized by a pneumostome located at the margin between the dorsal notum and the ventral hyponotum. Platevindex Baker, 1938 applies to a clade including species with a distinctly flattened body and a narrow foot. Semperoncis Starobogatov, 1976 applies to species characterized by a very different anatomy and which are adapted to terrestrial life in the Philippines (Dayrat 2010). And, finally, Melayonchis Dayrat & Goulding, 2017 applies to a distinct clade including slugs with a different anatomy (Dayrat et al. 2017)., Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 19-20, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525, {"references":["Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880],","Labbe A. 1934 a. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Dayrat B. 2009. Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa 2068: 1 - 26.","Dayrat B., Zimmermann S. & Raposa M. 2011 b. Systematic revision of the Onchidiidae from the tropical Eastern Pacific. Journal of Natural History 45: 939 - 1003. https: // doi. org / 10.1080 / 00222933.2010.545486","Dayrat B., Goulding T. C., Apte D., Bhave V., Comendador J., Ngo X. Q., Tan S. K. & Tan S. H. 2016. Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca, Gastropoda, Pulmonata, Onchidiidae). ZooKeys 636: 1 - 40. https: // doi. org / 10.3897 / zookeys. 636.8879","Plate L. von. 1893. Studien uber opisthopneumone Lungenschnecken. II. Die Oncidiiden. Zoologische Jahrbucher, Anatomie 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 22 Dec. 2018].","Dayrat B. 2010. Anatomical re-description of the terrestrial onchidiid slug Semperoncis montana (Plate, 1893). Malacologia 52: 1 - 20. https: // doi. org / 10.4002 / 040.052.0101"]}

Paromoionchis tumidus (Semper, 1880) comb. nov. Figs 7 ���25 Onchidium tumidum Semper, 1880: 262 ���263, pl. 20, figs 3���4, pl. 23, fig. 4. Onchidium samarense Semper, 1880: 268 ���269, pl. 20, figs 9, 13, pl. 23, fig. 7. Syn. nov. Onchidium mertoni Simroth, 1918: 294 ���296, pl. XX, figs 43���47. Syn. nov. Onchidium hongkongense Britton, 1984: 188 ���190, figs 6���7. Syn. nov. Onchidium samarense ��� Semper 1882: 268���269, pl. 21, fig. 5. Material examined Type material SINGAPORE ��� lectotype (here designated; 28/ 22 mm); ZMB 39019 a ��� 15 paralectotypes; ZMB 39019 b ��� 2 paralectotypes; NHMD 300305 ��� 1 paralectotype; SMF 333603 /1. AUSTRALIA ��� 2 paralectotypes; Queensland, Mackay; ZMB 39020. Other type material PHILIPPINES ��� lectotype of Onchidium samarense (here designated; 22/ 17 mm); Samar Island, Palapa harbor; ZMB 39025 a ��� 2 paralectotypes of O. samarense (24/20 and 20/ 15 mm); same locality as lectotype; ZMB 39025 b. INDONESIA ��� lectotype of Onchidium mertoni (here designated; 15/ 9 mm); Aru Islands, Kobroor, Sungai; 5 Jan. 1908; ZMB 121591 a ��� 4 paralectotypes of O. mertoni (14/8, 14/10, 15/14 and 14/ 10 mm); same data as for lectotype; ZMB 121591 b. CHINA ��� holotype of Onchidium hongkongense (17/ 13 mm); Hong Kong; NHM 1982290 ��� 15 paratypes; same locality as holotype; NHM 1982291 to 1982292. Notes on type material Onchidium tumidum. Lectotype, 28/ 22 mm, designated here (ZMB 39019 a). All other syntypes become paralectotypes (the 15 paralectotypes from the same lot are now ZMB 39019 b). According to the original description, the type material included 42 specimens from Singapore and an unknown number of specimens from Port Mackay, Queensland, Australia. A total of 21 syntypes were located in museum collections: 19 specimens from Singapore (16 specimens, ZMB 39019; 2 specimens, NHMD 300305; 1 specimen, SMF 333603 /1) and 2 specimens from Mackay (ZMB 39020). There also are two possible syntypes from Australia (ZMH 27480 /2). Two similar species of Paromoionchis gen. nov. are found at Port Mackay, P. tumidus and P. daemelii, which anatomically can only be distinguished based on the insertion of the retractor muscle of the penis. In the lectotype designated here from Singapore, the retractor muscle inserts near the heart, exactly as in the species described here. However, in one of the two paralectotypes of P. tumidus from Mackay (ZMB 39020), the retractor muscle is vestigial, as in P. daemelii (in the other paralectotype from Mackay, the male apparatus was destroyed prior to the present investigation and could not be examined). Hence, it was necessary to designate a lectotype from Singapore in order to clarify the application of P. tumidus. Note that the type material was fixed in formalin more than 130 years ago and no DNA sequencing could be attempted. Onchidium samarense. Lectotype, 22/ 17 mm, designated here (ZMB 39025 a). The two other syntypes become paralectotypes (ZMB 39025 b). According to the original description, the type material included only two specimens from the same locality in Samar, Philippines. However, the jar with the type material currently contains three similar-looking specimens (syntypes), all of which were dissected prior to the present study. It is not excluded that the original description was based on only two of those three specimens but it is also possible that Semper himself identified all three specimens as O. samerense [sic] (with a minor typo in the original description). The lectotype still contains all its internal organs, including the male copulatory parts. One paralectotype (24/ 20 mm) is mostly destroyed, with no internal organs left except the digestive gland (a few destroyed pieces of organs are in a vial). The other paralectotype (20/ 15 mm) still contains internal organs, but the male parts are missing. Our observations and comments are mostly based on the only specimen with male parts; hence its designation as a lectotype. Note that the type material was fixed in formalin more than 130 years ago and no DNA sequencing could be attempted. Note also that if, in the future, Onchidium samarense were to be regarded as a valid species name in Paromoionchis gen. nov., the specific name samarense (neuter) would need to become samarensis (masculine). Onchidium mertoni. Lectotype, 15/ 9 mm, designated here (ZMB 121591 a). The four other syntypes become paralectotypes (ZMB 121591 b). Simroth mentioned in the original description that all five specimens were very hard. Indeed, it seems that they dried out at some point and they are very poorly preserved. The lectotype designated here is the only specimen that is complete. It was partially dissected for the present study (the penial hooks, identical to those of O. tumidum, are illustrated here). Two paralectotypes (14/8 and 14/ 10 mm) were dissected prior to the present study and are completely empty. Two other paralectotypes (15/14 and 14/ 10 mm) are in very poor condition (the body is extremely hard and the digestive system is partly outside the body through the foot). A lectotype is designated here to clarify the application of the name O. mertoni because several species of Paromoionchis gen. nov. are potentially sympatric in the Aru Islands and so it cannot be excluded that the five original syntypes belong to different species. Note that the type material was fixed in formalin more than 100 years ago and no DNA sequencing could be attempted. Onchidium hongkongense. Holotype, 17/ 13 mm, by original designation (NHM 1982290) and 15 paratypes (NHM 1982291, NHM 1982292). The holotype is largely destroyed due to prior dissection, likely by Britton. Large parts of the notum and of the reproductive organs are missing. Even though it is mostly destroyed, the digestive system is confirmed to be of type II. A few paratypes were checked for the present study and their anatomy matches that of the holotype. Note that the type material was fixed in formalin more than 40 years ago and no DNA sequencing could be attempted. Note also that the specific name hongkongensis (masculine or feminine gender) originally used by Britton is corrected to hongkongense (neuter) for gender agreement with Onchidium. Should Onchidium hongkongense ever become a valid species name in Paromoionchis gen. nov., hongkongense would then need to be changed back to hongkongensis. Other material AUSTRALIA ��� New South Wales ��� 1 spec. (20/15 [1522] mm); Sydney, Pittwater, Careel Bay; 33��37.323��S, 151��19.878��E; 24 Nov. 2011; station 40; supratidal zone on margin of salt marsh, mangrove patch on side of creek; AM C.468918.005 ��� 1 spec. (35/20 [1529] mm); Sydney, Hawkesbury River, Cheero Point; 33��30.687��S, 151��11.669��E; 25 Nov. 2011; station 42; open mangrove with old logs; AM C.468924.001 ��� 1 spec. (33/20 [1528] mm); same data as for preceding; AM C.468923.002 ��� 1 spec. (32/20 [1530] mm); same data as for preceding; AM C.468925.001. ��� Northern Territory ��� 1 spec. (45/32 [1634] mm); Darwin, near Channel Island Road; 12��34.979��S, 130��55.992��E; 16 Aug. 2012; station 65; sequence of Sonneratia, Rhizophora and Ceriops; NTM P.57620 ��� 1 spec. (40/25 [1686] mm); Darwin, end of Channel Island Road; 12��33.557��S, 130��52.894��E; 17 Aug. 2012; station 66; sequence of Sonneratia, Rhizophora and Ceriops; NTM P.57621 ��� 1 spec. (42/38 [1638] mm); same data as for preceding; NTM P.57623 ��� 2 spec. (30/17 [1705] and 17/12 [1645] mm); Darwin, close to Tiger Brenan Road (small service road); 12��28.782��S, 130��54.750��E; 19 Aug. 2012; station 69; high tidal Ceriops; NTM P.57622 ��� 1 spec. (36/22 [1651] mm); Darwin, Elizabeth Road; 12��32.893��S, 130��57.642��E; 20 Aug. 2012; station 70; Ceriops and old logs in Rhizophora forest; NTM P.57624. ��� Queensland ��� 1 spec. (45/30 [2562] mm); Cairns, Yorkey���s Knob; 16��48.558��S, 145��42.768��E; 17 Jun. 2013; station 101; hard, red mud with grasses; MTQ ��� 1 spec. (45/30 [2602] mm); Townsville, Magnetic Island; 19��09.938��S, 146��49.029��E; 24 Jun. 2013; station 109; water on the mud; MTQ ��� 1 spec. (15/10 [2627] mm); Bowen; 20��00.658��S, 148��15.878��E; 1 Jul. 2013; station 115; back of mangrove across from beach, dense Rhizophora, Avicennia trees with soft mud around; MTQ ��� 1 spec. (55/30 [2637] mm); Bowen; 20��00.913��S, 148��15.745��E; 1 Jul. 2013; station 116; mangrove away from ocean, small area of open Avicennia mangrove, surrounded by Rhizophora; MTQ ��� 1 spec. (20/10 [2652] mm); Bowen, Doughty Creek; 20��01.264��S, 148��14.345��E; 2 Jul. 2013; station 117; narrow Avicennia and Rhizophora mangrove, by creek, some muddy areas and some very sandy; MTQ ��� 1 spec. (35/20 [2657] mm); Bowen; 20��01.478��S, 148��14.224��E; 3 Jul. 2013; station 119; Rhizophora and Avicennia mangrove; MTQ ��� 1 spec. (30/20 [2701] mm); Mackay; 20��08.511��S, 149��12.076��E; 8 Jul. 2013; station 125; large, dense and sandy mangrove and, by side of river, small strip of mud with Avicennia and Rhizophora; MTQ ��� 1 spec. (30/25 [1531] mm); Thirsty Sound, Plum Tree, beach in front of Endeavour Park; 22��08.144��S, 150��01.856��E; 14 Sep. 2002; I. Loch, D.L. Beechey and A.C. Miller leg.; sheltered, muddy cobble shore; AM C.575588. BRUNEI DARUSSALAM ��� 3 spec. (55/30 [1036], 35/20 [1035] and 20/15 [1062] mm); Pulau Pyatan, Teluk Brunei; 04��55.246��N, 115��02.764��E; 27 Jul. 2011; station 32; open Avicennia and Rhizophora mangrove, with hard mud; BDMNH. INDIA ��� 1 spec. (26/17 [1119] mm); Andaman Islands, Middle Andaman, Shantipur, Kadamtala; 12��19.843��N, 092��46.377��E; 12 Jan. 2011; station 58; open area with hard mud and many old logs, next to a mangrove with medium trees; BNHS 88. INDONESIA ��� Sumatra ��� 1 spec. (24/15 [1732] mm); Kualapenet; 05��16.275��S, 105��51.287��E; 17 Oct. 2012; station 77; narrow band of mangrove between ocean and fish ponds; UMIZ 0 0 121 ��� 2 spec. (35/20 [1754] and 26/16 [1755] mm); Bakauheni; 05��50.560��S, 105��46.200��E; 21 Oct. 2012; station 81; small mangrove, not far from road and next to large harbor, very impacted mangrove; UMIZ 0 0 122 ��� 1 spec. (38/30 [1794] mm); same data as for preceding; UMIZ 0 0 138 ��� 1 spec. (20/12 [1798] mm); S of Bandar Lampung; 05��32.66��S, 105��15.113��E; 28 Oct. 2012; station 83; high intertidal, fairly dense roots with some Avicennia and Nypa, edge of mangrove by road; UMIZ 0 0 123. ��� Sulawesi ��� 2 spec. (25/15 [2200] and 20/12 [2201] mm); Tamperong; 01��41.513��N, 125��00.797��E; 12 Mar. 2013; station 87; muddy mangrove with small Rhizophora in dense patches; UMIZ 0 0 124 ��� 1 spec. (27/15 [2240] mm); Sondaken; 01��21.777��N, 124��32.594��E; 13 Mar. 2013; station 89; sand, small rocks, pieces of wood outside narrow coastal mangrove of mostly Rhizophora; UMIZ 0 0 125 ��� 1 spec. (30/20 [2345] mm); Makassar, Tallo mangrove; 05��06.117��S, 119��26.777��E; 21 Mar. 2013; station 92; small mangrove used as outhouse by village, very impacted with trash; UMIZ 0 0 126 ��� 1 spec. (20/13 [2355] mm); Barru; 04��25.437��S, 119��35.953��E; 22 Mar. 2013; station 93; forest of mostly Avicennia and Rhizophora, with hard and sandy mud; UMIZ 0 0 127. ��� Ambon ��� 1 spec. (25/15 [3541] mm); Lateri; 03��38.261��S, 128��14.716��E; 12 Feb. 2014; station 128; mudflat next to small creek in low intertidal of mangrove preserve; UMIZ 0 0 128 ��� 3 spec. (45/30 [2832], 22/12 [2839] and 35/22 [2840] mm); Lateri; 03��38.237��S, 128��14.783��E; 14 Feb. 2014; station 131; muddy mangrove with Rhizophora; UMIZ 0 0 129. ��� Seram ��� 2 spec. (20/15 [2874] and 30/15 [2875] mm); Kawa; 02��58.240��S, 128��07.066��E; 18 Feb. 2014; station 135; mud next to a seawall adjacent to a mangrove; UMIZ 0 0 130. ��� Lombok ��� 2 spec. (30/20 [2950] and 20/12 [2952] mm); Tanjung Batu village; 08��45.748��S, 116��02.892��E; 24 Mar. 2014; station 145; Avicennia forest; UMIZ 0 0 131 ��� 1 spec. (20/14 [2961] mm); Seriwe Bay; 08��51.960��S, 116��32.838��E; 25 Mar. 2014; station 146; Avicennia mangrove with hard mud and rocks; UMIZ 0 0 132 ��� 1 spec. (18/10 [2960] mm); same data as for preceding; UMIZ 0 0 139. ��� Bali ��� 1 spec. (25/14 [3051] mm); Denpasar; 08��47.435��S, 115��13.197��E; 1 Apr. 2014; station 153; large mangrove by road, very soft mud; UMIZ 0 0 133 ��� 1 spec. (30/20 [3070] mm); Denpasar; 08��46.126��S, 115��10.803��E; 2 Apr. 2014; station 154; large mangrove by road, with shallow mud; UMIZ 0 0 134. ��� Halmahera ��� 1 spec. (25/15 [5082] mm); Akelamo; 01��01.329��N, 127��39.091��E; 10 Mar. 2015; station 207; sandymuddy beach at margin of mangrove near village; UMIZ 0 0 135 ��� 2 spec. (50/35 [5102] and 55/35 [5103] mm); Buli; 00��55.446��N, 128��20.612��E; 16 Mar. 2015; station 212; logged area in front of old Rhizophora forest, by the road; UMIZ 0 0 136 ��� 1 spec. (55/30 [5042] mm); Buli; 00��55.367��N, 128��20.647��E; 17 Mar. 2015; station 213; tall and old Rhizophora forests, high intertidal; UMIZ 0 0 137. JAPAN ��� 1 spec. (22/10 [3761] mm); Ehime Prefecture, Misho Bay; 32��57.634��N, 132��33.205��E; 4 Aug. 2014; station o28; mudflats; NSMT Mo 78984. MALAYSIA ��� 1 spec. (40/25 [963] mm); Peninsular Malaysia, Nibong Tebal, Pulau Burung; 05��12.488��N, 100��25.564��E; 11 Jul. 2011; station 17; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 57 ��� 1 spec. (18/12 [928] mm); E Peninsular Malaysia, Balok; 03��53.219��N, 103��21.978��E; 14 Jul. 2011; station 19; mostly Rhizophora, with some Avicennia, hard mud with shallow pools, patches of soft mud; USMMC 0 0 0 58. PAPUA NEW GUINEA ��� 1 spec. (18/14 [5432] mm); Madang, Meiro River, near airport; 05��12.2��S, 145��47.4��E; 5 Nov. 2012; MNHN expedition Papua Niugini leg.; station PM01; Nypa palm swamp; MNHN IM-2013-10478 ��� 1 spec. (17/12 [5433] mm); same data as for preceding; MNHN IM-2013- 10479. PHILIPPINES ��� Luzon ��� 1 spec. (26/18 [3610] mm); Lian, Batangas; 13��58.130��N, 120��37.471��E; 5 Jul. 2014; station 179; narrow and impacted mangrove of Avicennia near village, very sandy, little to no mud; PNM 0 41261 ��� 2 spec. (30/20 [3171] and 25/15 [3192] mm); Nasugbu, Batangas; 14��10.714��N, 120��36.817��E; 6 Jul. 2014; station 182; near village, well-preserved and dense forest of Avicennia and Rhizophora; PNM 0 41255 ��� 1 spec. (22/14 [3172] mm); same data as for preceding; PNM 0 41262 ��� 2 spec. (30/20 [3200] and 35/22 [3205] mm); Calantagan, Batangas; 13��55.319��N, 120��37.260��E; 7 Jul. 2014; station 183; rocks next to Avicennia and Rhizophora forest; PNM 0 41256 ��� 1 spec. (30/18 [3202] mm); same data as for preceding; PNM 0 41263 ��� 1 spec. (35/22 [3222] mm); Calantagan, Batangas; 13��53.278��N, 120��37.124��E; 8 Jul. 2014; station 184; narrow forest on the shore, Avicennia and young Rhizophora; PNM 0 41257 ��� 1 spec. (33/15 [3229] mm); same data as for preceding; PNM 0 41264 ��� 1 spec. (27/18 [3237] mm); Calantagan, Batangas; 13��51.264��N, 120��37.383��E; 8 Jul. 2014; station 185; next to village, impacted, narrow Avicennia mangrove by the shore; PNM 0 41265. ��� Bohol ��� 1 spec. (40/25 [3344] mm); Mabini; 09��51.532��N, 124��31.685��E; 17 Jul. 2014; station 194; narrow mangrove on edge of fish ponds, tall Rhizophora and Avicennia trees, many old logs; PNM 0 41258 ��� 1 spec. (26/15 [3371] mm); Mabini; 09��51.586��N, 124��34.155��E; 18 Jul. 2014; station 196; Avicennia and Sonneratia open forest with sand, algae and coral rubble; PNM 0 41259 ��� 1 spec. (30/18 [3416] mm); Maribojoc; 09��44.280��N, 123��49.389��E; 20 Jul. 2014; station 202; uplifted coral rubble with sand and algae, near Sonneratia trees; PNM 0 41260. VIETNAM ��� 2 spec. (45/30 [5619] and 40/30 [5682] mm); Nha Trang; 12��12.778��N, 109��09.572��E; 27 Jul. 2015; station 237; small strip of mud with a few Rhizophora trees next to a small river, by fish ponds and houses; ITBZC IM 0 0 0 19 ��� 1 spec. (25/15 [5642] mm); Nha Trang; 12��24.168��N, 109��10.058��E; 29 Jul. 2015; station 239; mostly Avicennia and some small Rhizophora, with shallow mud; ITBZC IM 0 0 0 20. Color and morphology of live animals (Figs 7���10) Live animals of units #1 and #2 are often abundantly covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, light to dark. That background can be homogenous or clearly mottled with darker or lighter areas and, occasionally, also with red areas. In addition, in some animals the tip of the dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot varies from gray (light or dark) to yellow or orange. The hyponotum is almost always yellow, from pale yellow to bright yellow and even orange. This variable yellow component can cover the entire hyponotum or just an outer ring (the inner ring being light to dark gray). The color of the foot and of the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are brown (variable from light to dark) and may or may not be speckled with tiny white dots, exactly like the head. The ocular tentacles are short (just a few millimeters long). No live pictures were available for unit #3, so the following description is based on preserved specimens (Fig. 10). It is possible that bright colors (yellow, orange) were lost during preservation on both the ventral and dorsal sides. The background of the dorsal notum is brown, mottled with darker or lighter areas. The foot is light gray. The hyponotum is gray-brown, with a reddish hue on the margin (which could possibly be orange in live animals). The color of the ocular tentacles (retracted, likely short) cannot be determined. Generally speaking, the dorsal notum of any given live animal can rapidly change from almost perfectly smooth to covered by many papillae. However, when animals are not disturbed, the dorsum is usually covered by papillae of various sizes. In some animals, larger papillae may be arranged in two longitudi, Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 22-44, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525, {"references":["Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880],","Simroth H. 1918. Uber einige Nacktschnecken vom Malayischen Archipel von Lombok an ostwarts bis zu den Gesellschafts-Inseln. Abhandlungen herausgegeben von der Senckenbergischen Naturforschenden Gesellschaft 35: 261 - 302. Available from https: // biodiversitylibrary. org / page / 48256899 [accessed 22 Dec. 2018].","Britton K. M. 1984. The Onchidiacea (Gastropoda, Pulmonata) of Hong Kong with a worldwide review of the genera. Journal of Molluscan Studies 50: 179 - 191. https: // doi. org / 10.1093 / oxfordjournals. mollus. a 065863","Johnson R. I. 1969. Semper's Reisen im Archipel der Philippinen, wissenschaftliche Resultate, 1867 - 1916. A complete collation. Journal of the Society for the Bibliography of Natural History 5: 144 - 147. https: // doi. org / 10.3366 / jsbnh. 1969.5.2.144","Plate L. von. 1893. Studien uber opisthopneumone Lungenschnecken. II. Die Oncidiiden. Zoologische Jahrbucher, Anatomie 7: 93 - 234. Available from https: // biodiversitylibrary. org / page / 11175213 [accessed 22 Dec. 2018].","Bretnall W. 1919. Onchidiidae from Australia and the South-Western Pacific Islands. Records of the Australian Museum 12: 303 - 328. https: // doi. org / 10.3853 / j. 0067 - 1975.12.1919.888","Labbe A. 1934 a. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Hoffmann K. 1928. Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher, Jena 55: 29 - 118.","Tapparone-Canefri C. 1883. Fauna malacologica delle Nuova Guinea e delle isole adiacenti. Annali del Museo Civico di Storia Naturale di Genova 19: 1 - 313. Available from https: // biodiversitylibrary. org / page / 10812600 [accessed 22 Dec. 2018].","Boettger C. R. 1923. Die Landschneckenfauna der Aru- und der Kei-Inseln. Abhandlungen herausgegeben von der Senckenbergischen Naturforschenden Gesellschaft 35: 353 - 418. Available from https: // biodiversitylibrary. org / page / 48257011 [accessed 22 Dec. 2018].","Dayrat B., Goulding T. C., Apte D., Bhave V., Comendador J., Ngo X. Q., Tan S. K. & Tan S. H. 2016. Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca, Gastropoda, Pulmonata, Onchidiidae). ZooKeys 636: 1 - 40. https: // doi. org / 10.3897 / zookeys. 636.8879"]}

Paromoionchis boholensis Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: 104C35EF-FBF9-4EC2-A5A8-89AC30009270 Figs 31–40 Etymology Paromoionchis boholensis gen. et sp. nov. is named after Bohol Island, where the type locality is. Material examined Holotype PHILIPPINES • holotype (28/18 [3288] mm); Bohol, Maribojoc; 09°43.645´N, 123°50.988´E; 15 Jul. 2014; station 193; small island at end of boardwalk, sandy mud and rocks in back of mangrove; PNM 0 41266. Other material INDONESIA – Sulawesi •2spec.(35/22[2128]and37/20[2129]mm); Wori; 01°36.055´N, 124°51.730´E; 9 Mar. 2013; station 84; tall mangrove forest of Sonneratia and Avicennia, with old logs; UMIZ 0 0 141 • 1 spec. (9/6 [2175] mm); Bahoi; 01°43.355´N, 125°01.232´E; 10 Mar. 2013; station 85; sand, small rocks and pieces of wood, near narrow coastal mangrove; UMIZ 0 0 142 • 1 spec. (20/13 [2199] mm); Tamperong; 01°41.513´N, 125°00.797´E; 12 Mar. 2013; station 87; muddy mangrove with small and dense Rhizophora; UMIZ 0 0 143 • 1 spec. (12/8 [2316] mm); Mantehang; 01°41.880´N, 124°46.741´E; 15 Mar. 2013; station 91; Sonneratia at low intertidal and Rhizophora at high intertidal; UMIZ 0 0 144 • 1 spec. (20/13 [2360] mm); Panikkiang Island; 04°21.730´S, 119°35.630´E; 25 Mar. 2013; station 94; Rhizophora, Avicennia, Sonneratia and old logs; UMIZ 0 0 145. – Ambon • 3 spec. (40/25 [2849], 45/30 [2850] and 45/25 [2851] mm); Wai; 03°34.652´S, 128°19.526´E; 15 Feb. 2014; station 132; narrow band of old Avicennia trees on sandy mud, old logs on ground; UMIZ 0 0 146. – Seram • 1 spec. (45/28 [2884] mm); Piru; 03°04.072´S, 128°11.362´E; 19 Feb. 2014; station 136; Sonneratia mangrove next to fish market, next to beach of palms and ferns, with cattle roaming around; UMIZ 0 0 147. – Kei Islands • 2 spec. (10/8 [2896] and 17/8 [2901] mm); Un; 05°38.273´S, 132°45.738´E; 23 Feb. 2014; station 137; Bruguiera and Rhizophora, some muddy areas and some with coral rubble; UMIZ 0 0 148 • 2 spec. (15/10 [2903] and 18/8 [2911] mm); Un; 05°38.273´S, 132°45.738´E; 25 Feb. 2014; station 140; back of mangrove, on rocks, on mud, inside logs and under leaf litter; UMIZ 0 0 149 • 3 spec. (40/22 [3565], 30/20 [2935] and 40/22 [2937] mm); Fiditan; 05°35.957´S, 132°45.112´E; 28 Feb. 2014; station 144; rocks behind muddy Rhizophora mangrove; UMIZ 0 0 150. – Bali • 1 spec. (35/17 [3117] mm); Gilimanuk; 08°10.156´S, 114°26.652´E; 4 Apr. 2014; station 156; muddy mangrove with Rhizophora and Avicennia trees; UMIZ 0 0 140. – Halmahera • 1 spec. (25/16 [5019] mm); Sofifi; 00°45.473´N, 127°35.897´E; 8 Mar. 2015; station 205; Sonneratia mangrove, with dense roots and hard mud; UMIZ 0 0 151 • 2 spec. (47/30 [5140] and 35/22 [5146] mm); Gamkonora; 01°26.911´N, 127°31.625´E; 21 Mar. 2015; station 219; mostly Rhizophora mangrove with some sandy areas and some open muddy spaces; UMIZ 0 0 152. PHILIPPINES – Luzon • 1 spec. (25/18 [3609] mm); Lian, Batangas; 13°58.130´N, 120°37.471´E; 5 Jul. 2014; station 179; narrow and impacted mangrove of Avicennia near village, very sandy, little to no mud; PNM 0 41267. – Bohol • 2 spec. (16/9 [3283] and 17/10 [3619] mm); same data as for holotype; PNM 0 41268 • 3 spec. (20/15 [3369], 35/18 [3372] and 27/20 [3411] mm); Mabini; 09°51.586´N, 124°34.155´E; 18 Jul. 2014; station 196; open Avicennia and Sonneratia forest with sand, algae and coral rubble; PNM 0 41269 • 5 spec. (30/22 [3412], 30/23 [3413], 40/17 [3417], 40/20 [3422] and 42/25 [3423] mm); Maribojoc; 09°44.280´N, 123°49.389´E; 20 Jul. 2014; station 202; uplifted coral rubble with sand and algae, near Sonneratia trees; PNM 0 41270. Color and morphology of live animals (Figs 31–32) Live animals are often covered with mud, in which case their dorsal color can hardly be seen. In unit #1, the background of the dorsal notum is brown, occasionally mottled with darker or lighter areas, while in unit #2 it ranges from very light brown (almost white) to dark brown, mottled or not. In some animals, there is a reddish hue on the margin of the dorsal notum (unit #1). In addition, in most animals the tip of the dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot is orange (unit #1) or varies from gray to yellow and orange (unit #2). The hyponotum is also orange, often with a darker ring on the margin which may be bright red (unit #1) or homogenously gray, yellow, or orange, but can also display a mix of two or three of those colors (unit #2). The color of both the foot and the hyponotum of an individual can change very rapidly, especially when disturbed. The ocular tentacles are reddish brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). Digestive system (Figs 33A, 34A, 35–36) Radulae measure up to 4.5 mm (unit #1) and 4 mm (unit #2) in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 33 B–C, 34B–C, 37–38) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle) and the accessory penial gland (flagellum and hollow spine). The hollow spine of the accessory penial gland is narrow, elongated, slightly curved. Its base is conical. Its diameter is approximately 50 to 70 μm for most of its length and 100–130 μm at its base (unit #1) and approximately 70 to 80 μm for most of its length and 150–200 μm at its base (unit #2). Its length ranges from 1 mm ([3288] PNM 0 41266, holotype) to 1.2 mm ([3372] PNM 041269) in unit #1 and from 1.1 mm ([5019] UMIZ 00151) and 1.3 mm ([3117] UMIZ 00140) to 1.8 mm ([2911] UMIZ 0 0 149, [5140] UMIZ 00152) in unit #2, and its shape does vary between individuals (Fig. 38). The penial sheath is narrow and elongated. The retractor muscle is vestigial, i.e., with its distal end being free in the visceral cavity, with no clear insertion (unit #1), or absent or vestigial (unit #2). The deferent duct is highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, smooth (no hooks) and hollow tube of approximately 200 μm in diameter. Distinctive diagnostic features Externally, the color of the foot and hyponotum can help one to identify Paromoionchis boholensis gen. et sp. nov., but unfortunately it is not fully reliable. Specimens with a bright orange foot and hyponotum are only found in P. boholensis gen. et sp. nov., especially in unit #1 but also in unit #2; the ventral side of P. tumidus, which is sympatric with P. boholensis (Fig. 6), can be orange but not bright orange. However, specimens with a more yellowish or greyish foot and hyponotum cannot be identified externally. The internal anatomy of P. boholensis gen. et sp. nov. (accessory penial gland, vestigial penial retractor muscle, penis with no hooks) is similar to that of P. daemelii. However, P. boholensis gen. et sp. nov. and P. daemelii do not overlap geographically, at least based on the present data. Thus, within its distribution range P. boholensis gen. et sp. nov. is the only species with this combination of internal characters. Indeed, the internal characters of the two species of Paromoionchis gen. nov. with which P. boholensis gen. et sp. nov. is sympatric (P. goslineri gen. et sp. nov. and P. tumidus) are different (Table 3). It must be noted that the known distribution of species of Paromoionchis gen. nov. may change as new records are found in the future and so the use of geographic data should only be used with caution for identification. Distribution (Fig. 6) Philippines (unit #1): Bohol (type locality), Luzon. Indonesia (unit #2): Ambon, Bali, Halmahera, Kei Islands, Seram, Sulawesi. Habitat (Figs 39–40) Unit #1 of Paromoionchis boholensis gen. et sp. nov. is found on sandy mud or sand with very little mud, in mangroves or near mangrove trees and is rare (it was found at only four stations). Unit #2 is found in open or dense mangroves, on soft or hard mud, as well as on muddy sand and is common (but not as common as P. tumidus unit #1).

Paromoionchis goslineri Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: E375A628-4AE6-4E10-B424-D4BBF58F8941 Figs 45���51 Etymology Paromoionchis goslineri gen. et sp. nov. is dedicated to Dr. Terry Gosliner, Senior Curator at the California Academy of Sciences, San Francisco, California, USA, who has been exploring the marine life of the Batangas region for many years, where this new species was found, and, more importantly, for years ago providing the first author with a great post-doctoral opportunity to focus on alpha-taxonomy. Material examined Holotype PHILIPPINES ��� holotype (25/15 [3233] mm); Luzon, Calantagan, Batangas; 13��51.264��N, 120��37.383��E; 8 Jul. 2014; station 185; next to village, impacted narrow mangrove forest of Avicennia by the shore; PNM 0 41271. Other material INDONESIA ��� Sulawesi ��� 1 spec. (20/14 [2210] mm); Bahoi; 01��43.355��N, 125��01.232��E; 12 Mar. 2013; station 88; sand, small rocks and pieces of wood outside narrow coastal mangrove; UMIZ 0 0 161 ��� 1 spec. (18/10 [2241] mm); Sondaken; 01��21.777��N, 124��32.594��E; 13 Mar. 2013; station 89; mostly Rhizophora, with sand, small rocks and pieces of wood outside narrow coastal mangrove; UMIZ 0 0 153. ��� Bali ��� 3 spec. (22/15 [3060], 22/15 [3066] and 27/20 [3068] mm); Denpasar; 08��46.126��S, 115��10.803��E; 2 Apr. 2014; station 154; large mangrove by road, with shallow mud; UMIZ 0 0 154 ��� 4 spec. (20/12 [3072], 17/10 [3074], 22/14 [3078] and 24/14 [3079] mm); Gilimanuk; 08��10.259��S, 114��26.606��E; 3 Apr. 2014; station 155; from high intertidal with water pools and many mounds up to shore with sand and rocks; UMIZ 0 0 155 ��� 2 spec. (22/10 [3118] and 37/20 [3120] mm); Gilimanuk; 08��10.156��S, 114��26.652��E; 4 Apr. 2014; station 156; muddy mangrove with Rhizophora and Avicennia trees; UMIZ 0 0 156. ��� Timor ��� 2 spec. (12/7 [5890] and 15/7 [5891] mm); Oesapa; 10��08.732��S, 123��38.096��E; 11 Jul. 2016; station 250; sandy part of mangrove, with Sonneratia and Avicennia; UMIZ 0 0 157. ��� Halmahera ��� 2 spec. (24/16 [5072] and 32/23 [5073] mm); Dodinga; 00��51.348��N, 127��38.504��E; 9 Mar. 2015; station 206; back of mangrove, high intertidal, with ferns and mounds; UMIZ 0 0 158 ��� 1 spec. (35/22 [5145] mm); Gamkonora; 01��26.911��N, 127��31.625��E; 21 Mar. 2015; station 219; mostly Rhizophora, with some sandy and open muddy areas; UMIZ 0 0 159. ��� Ambon ��� 1 spec. (12/7 [3555] mm); Wai; 03��34.652��S, 128��19.526��E; 15 Feb. 2014; station 132; narrow band of old Avicennia trees on sandy mud, with old logs; UMIZ 0 0 160. PHILIPPINES ��� Luzon ��� 2 spec. (22/15 [3221] and 20/16 [6049] mm); Calantagan, Batangas; 13��53.278��N, 120��37.124��E; 8 Jul. 2014; station 184; narrow forest on the shore, with Avicennia and young Rhizophora; PNM 0 41272 ��� 1 spec. (28/20 [3232] mm); same data as for holotype; PNM 0 41273. Color and morphology of live animals (Figs 45���46) Live animals are most often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is gray-brown, mottled with darker and lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be lighter (pale yellow or white). The foot and the hyponotum are dark or light gray. The color of both the foot and the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are gray-brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). The tip of dorsal papillae is usually white or pale yellow, but not always (in any case generally covered with mud). Digestive system (Figs 47A, 48A, 49���50) Radulae measure up to 2.6 mm (unit #1) and 2.2 mm (unit #2) in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 47 B���C, 48B���C) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle). An accessory penial gland is absent. The penial sheath is narrow and elongated. In unit #1, the retractor muscle is very short (much shorter than the penial sheath), inserting on the body wall near the nervous system, or vestigial (its distal end being free in the visceral cavity, with no clear insertion). In unit #2, the retractor muscle is long (as long as the penial sheath), inserting near the heart. The deferent duct is also highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, smooth (no hooks) and hollow tube of approximately 200 ��m in diameter. Distinctive diagnostic features Externally, Paromoionchis goslineri gen. et sp. nov. cannot be distinguished from other species of Paromoionchis gen. nov. The ventral side (foot and hyponotum) is gray, i.e., never yellow or orange. Unfortunately, a gray ventral side can occasionally be found in all other species of the genus, so the use of that color trait is not fully reliable for identification. However, the internal anatomy of P. goslineri gen. et sp. nov. (no accessory penial gland, thin penis with no hooks) is very distinctive and can be used for a fully reliable identification. The only other species of Paromoionchis gen. nov. without an accessory penial gland, P. penangensis gen. et sp. nov., differs greatly from P. goslineri gen. et sp. nov. anatomically because its penis is very large. Units #1 and #2 of P. goslineri gen. et sp. nov. differ slightly with respect to the penial retractor: it is short and thin, inserting near the nervous system, or even vestigial in unit #1, while it is as long as the penial sheath, inserting near the heart in unit #2. However, given that only four specimens could be dissected in unit #1, it is very possible that intermediates may be found in the future, especially considering that units #1 and #2 are widely distant geographically. Distribution (Fig. 6) Philippines (unit #1): Luzon (type locality). Indonesia (unit #2): Ambon, Bali, Halmahera, Sulawesi and Timor. Habitat (Fig. 51) Paromoionchis goslineri gen. et sp. nov. unit #1 is found on mud, in Avicennia forests near the shore and is rare (only four specimens are known from two stations). Unit #2 is found on soft and hard mud, in mangroves or in open areas near mangroves and is rare (except in Bali, where several specimens were found at a few stations)., Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 64-67, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525

Paromoionchis Dayrat & Goulding gen. nov. urn:lsid:zoobank.org:act: 4506A7F2-CC0B-4F23-8F5E-4DE2AA42B61F Type species Onchidium tumidum Semper, 1880, designated here. Diagnosis Body not flattened. No dorsal gills. Dorsal eyes present on notum. Retractable, central papilla (usually with four dorsal eyes) present, often raised above dorsal surface. Eyes at tip of short ocular tentacles. Male opening below right ocular tentacle and to its left. Foot wide. Pneumostome median, on ventral hyponotum. Intestinal loops of type II. Rectal gland absent. Accessory penial gland present or absent. When present, accessory penial gland with muscular sac. Penis with or without hooks. Differential diagnosis No external diagnostic feature unambiguously distinguishes Paromoionchis gen. nov. from all other genera (which is not surprising because many onchidiid species from different genera are very similar externally). However, Paromoionchis gen. nov. is characterized by a unique combination of internal and external characters: no dorsal gills, male opening below and to the left of the right eye tentacle, no rectal gland and intestinal loops of type II (see Labbé 1934a: 177, fig. 3, for a comparison of digestive types). According to our data, any onchidiid slug with this combination of characters must belong to a species of Paromoionchis gen. nov. Etymology The name Paromoionchis is a combination of parómoios (παρóμoιoς), which means ʻsimilarʼ in Greek (because members look very similar externally) and onchis, a word derived from the Greek onchos (ὁ ὂγκος) and one of the early names used to refer to onchidiid slugs. Gender Masculine, the gender of onchis (ICZN Art. 30.1.1), a word derived from the masculine Greek word ὁ ὂγκος (onchos), which means ʻmassʼ or ʻtumor.ʼ As a result (ICZN Art. 31.2), the ending of the specific name tumidum (a Latin adjective) must be changed from neuter (because Onchidium is a name of neuter gender) to masculine (tumidus). Distribution The new genus described here is distributed from the western coast of India in the west, all the way to the subtropical waters of Japan (~33° N), Papua New Guinea and the subtropical waters of southeastern Australia (~32° S) in the east (Fig. 6). We did not find Paromoionchis gen. nov. in South Africa, Madagascar or Mauritius, but it is possible that it is present in areas east of Papua New Guinea, such as Fiji and New Caledonia, where we did not collect. Habitat The five known species of Paromoionchis gen. nov. primarily live on mud, in or next to mangroves, which explains why three species have just been discovered now, because the mangroves of South- East Asia have been very poorly explored. Occasionally, these slugs can also be found in or on muddy logs, coral rubble, sandy mud or even sand with very little mud in it. Paromoionchis tumidus, which is widespread and very common, can be found in nearly all these habitats, even though the mud surface remains where it is most commonly found, like all other species of the genus. Because members of Paromoionchis gen. nov. prefer the mud surface, live animals are often covered with mud. Remarks A new generic name is needed because no existing name applies to the clade described here. Our remarks are based on the examination of all the type specimens available, especially those of the type species of all genera, the careful analyses of all the original descriptions (especially when no type specimens were available), and our ongoing taxonomic revision of each genus of the family. Three existing generic names are junior synonyms of Onchidella J.E. Gray, 1850, which is not found in the tropical Indo-West Pacific and is characterized by a completely different anatomy (Dayrat 2009; Dayrat et al. 2011b). Seven generic names apply to the clade including all the onchidiid slugs with dorsal gills, i.e., Peronia Fleming, 1822 (Dayrat 2009). Labella Starobogatov, 1976 is a junior synonym of Onchidium Buchannan, 1800, which applies to a distinct clade including three species (Dayrat et al. 2016). Paraoncidium Labbé, 1934 is a junior synonym of Onchidina Semper, 1882, which applies to a distinct monotypic genus from southeastern Australia (Dayrat & Goulding 2017). Peronina Plate, 1893 applies to a clade including slugs characterized by a pneumostome located at the margin between the dorsal notum and the ventral hyponotum. Platevindex Baker, 1938 applies to a clade including species with a distinctly flattened body and a narrow foot. Semperoncis Starobogatov, 1976 applies to species characterized by a very different anatomy and which are adapted to terrestrial life in the Philippines (Dayrat 2010). And, finally, Melayonchis Dayrat & Goulding, 2017 applies to a distinct clade including slugs with a different anatomy (Dayrat et al. 2017).

Paromoionchis penangensis Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: 840ABD3E-61AC-4B1E-9D83-B15A8099F0BA Figs 41–44 Etymology Paromoionchis penangensis gen. et sp. nov. is named after Penang Island, Malaysia, in the Strait of Malacca, which is the type locality. Material examined Holotype MALAYSIA • holotype (26/14 [6037] mm); Peninsular Malaysia, Penang, Pantai Acheh; 05°24.922´N, 100°11.571´E; 1 Aug. 2016; station 261; Avicennia mangrove, with both very soft mud and hard mud; USMMC 00059. Other material INDIA – Andaman Islands • 1 spec. (18/10 [1086] mm); Middle Andaman, Rangat, Yerrata, Saban; 12°27.451´N, 092°53.792´E; 10 Jan. 2011; station 56; open, impacted mangrove patch by a creek, near village, with medium trees and old logs; BNHS 92 • 2 spec. (18/8 [1100] and 9/6 [1101] mm); Middle Andaman, Rangat, Shyamkund; 12°28.953´N, 092°50.638´E; 11 Jan. 2011; station 57; by a large river, deep mangrove with tall trees, small creeks and plenty of old logs, next to a road and a small cemented bridge over a creek; BNHS 53 • 2 spec. (20/10 [1117] and 22/12 [1118] mm); Middle Andaman, Shantipur, Kadamtala; 12°19.843´N, 092°46.377´E; 12 Jan. 2011; station 58; open area with hard mud and many old logs, next to a mangrove with medium trees; BNHS 11 • 2 spec. (30/15 [1129] and 12/7 [1130] mm); South Andaman, Bamboo Flat, Shoal Bay; 11°47.531´N, 092°42.577´E; 13 Jan. 2011; station 59; open mangrove with medium trees, hard mud, dead logs, next to a road and a small cemented bridge for creek; BNHS 4. – Maharashtra • 1 spec. (35/20 [1167] mm); Watad; 17°15.791´N, 73°17.623´E; 23 Dec. 2011; station 46; Avicennia mangrove, by field, with deep and very watery mud; BNHS 46 • 3 spec. (30/18 [1177], 20/14 [1175] and 15/10 [1173] mm); same data as for preceding; BNHS 98 • 2 spec. (16/11 [1176] and 27/21 [1182] mm); Aare Ware; 17°04.404´N, 73°17.747´E; 24 Dec. 2011; station 47; mangrove with soft mud and some areas with pools, mostly Avicennia with a few small Rhizophora; BNHS 42. MALAYSIA – Peninsular Malaysia • 2 spec. (30/20 [5990] and 30/20 [5991] mm); Kuala Gula; 04°55.991´N, 100°26.917´E; 29 Jul. 2016; station 259; mostly Avicennia, a few Bruguiera and Rhizophora, along a creek, both soft and hard mud; USMMC 0 0 0 60 • 2 spec. (20/14 [957] and 15/10 [958] mm); Nibong Tebal, Pulau Burung; 05°12.488´N, 100°25.564´E; 11 Jul. 2011; station 17; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 61 • 1 spec. (48/35 [6020] mm); Nibong Tebal, Pulau Burung; 05°12.488´N, 100°25.564´E; 30 Jul. 2016; station 260; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 62 • 3 spec. (25/12 [6031], 25/18 [6033] and 25/16 [6039] mm); same data as for holotype; USMMC 0 0 0 63. Color and morphology of live animals (Fig. 41) Live animals are most often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, occasionally mottled with darker or lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be yellow. The foot is gray, occasionally with a light yellow hue. The hyponotum is uniform gray or gray (inner ring) and yellow (outer ring). The color of both the foot and the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few mm long). Digestive system (Figs 42A, 43) Radulae measure up to 3.2 mm in length. Examples of radular formulae are presented in Table 4. Reproductive system (Fig. 42 B–C) In the posterior (female) organs, the distal portion of the oviduct and of the duct to the spermatheca is wider than in other species, which makes sense given the wide penis. The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle). An accessory penial gland is absent. The penial sheath is large (at least ten times as large as the deferent duct). The retractor muscle is strong, long and inserts near the heart. The deferent duct is convoluted, with many loops. Inside the penial sheath, the penis is a large (wider than long), smooth (no hooks), muscular mass. Distinctive diagnostic features Externally, Paromoionchis penangensis gen. et sp. nov. cannot be reliably distinguished from other species of Paromoionchis gen. nov. Its distribution only overlaps with that of P. tumidus. Our data suggest that the tips of the dorsal papillae of P. penangensis gen. et sp. nov. tend to be paler yellow, while they tend to be brighter yellow in P. tumidus. However, the internal anatomy of P. penangensis gen. et sp. nov., especially the large penis inside the large penial sheath, is very distinct from that of all other species and reliably distinguishes it from P. tumidus. Distribution (Fig. 6) Malaysia: Peninsular Malaysia, Strait of Malacca (type locality). India: Andaman Islands (Bay of Bengal), Maharashtra (W coast of India). Habitat (Fig. 44) Paromoionchis penangensis gen. et sp. nov. is found on soft and hard mud, in mangroves or in open areas near mangroves. This species was only found at three stations in the Strait of Malacca, three stations in the Andaman Islands (Bay of Bengal), and three stations in Maharashtra (W coast of India). However, at each station it was found to be quite abundant.

Paromoionchis daemelii (Semper, 1880) comb. nov. Figs 26–30 Onchidium dämelii Semper, 1880: pl. 20, fig. 2. Onchidium dämelii – Semper 1882: 270–271, pl. 21, fig. 9. Material examined Type material AUSTRALIA • lectotype (here designated; 17/ 14 mm); New South Wales, Sydney; ZMB 31640 a • 1 paralectotype (17/ 17 mm); same locality as lectotype; ZMB 31640 b • 1 paralectotype (destroyed, dried); same locality as lectotype; ZMB 39035 • 2 paralectotypes (?); same locality as lectotype; ZMH 27476 /2. Notes on type material The lectotype, 17/ 14 mm, is designated here (ZMB 31640 a). All other syntypes become paralectotypes. According to the original description, the type material included only three specimens. However, five possible syntypes could be located in museum collections, all from Sydney, Australia: 2 specimens, one of which, dissected with male parts remaining inside (17/ 14 mm), is designated as lectotype (ZMB 31640 a) and the other one, still entire (17/ 17 mm), is a paralectotype (ZMB 31640 b); 1 specimen destroyed, in pieces and completely dried (ZMB 39035); and 2 specimens (ZMH 27476 /2), both entire. It is unclear exactly which specimens Semper used for the description, but it is safe to assume that the anatomical details he provided are based on the only two dissected specimens. Two species of Paromoionchis gen. nov. are present in Sydney, P. tumidus and the species described here, which are cryptic externally but distinct internally. Thus, the specimens that were not dissected by Semper could belong either to P. tumidus or to the species treated here. Hence the necessity of designating a lectotype in order to clarify the application of the name Onchidium daemelii. Other material AUSTRALIA – New South Wales • 1 spec. (37/25 [1511] mm); Sydney, Middle Harbour, N of Roseville Bridge, W bank; 33°46.332´S, 151°12.106´E; 23 Nov. 2011; station 38; open mangrove, in old logs on the mud; AM C.468910.001 • 1 spec. (17/10 [1510] mm); same data as for preceding; AM C.468911.001 • 1 spec. (65/35 [1518] mm); Sydney, Pittwater, Church Point, next to yacht club; 33°39.107´S, 151°17.363´E; 24 Nov. 2011; station 39; muddy sand next to small patch of mangrove and rocks on sandy beach; AM C.468913.001 • 1 spec. (60/35 [1519] mm); same data as for preceding; AM C.468917.001 • 1 spec. (28/18 [1515] mm); same data as for preceding; AM C.468914.001 • 1 spec. (52/28 [1514] mm); same data as for preceding; AM C.468912.002 • 1 spec. (40/20 [1512] mm); same data as for preceding; AM C.468912.003 • 1 spec. (50/25 [1521] mm); Sydney, Pittwater, Careel Bay; 33°37.323´S, 151°19.878´E; 24 Nov. 2011; station 40; supratidal zone on the margin of salt marsh, mangrove patch on side of creek; AM C.468919.001. – Queensland • 2 spec. (15/12 [1532] and 8/6 [1533] mm); Thirsty Sound, Plum Tree, beach in front of Endeavour Park; 22°08.144´S, 150°01.856´E; 14 Sep. 2002; I. Loch, D.L. Beechey and A.C. Miller leg.; sheltered, muddy cobble shore; AM C.415270 • 1 spec. (8/6 [2668] mm); Bowen, Doughty Creek; 20°01.478´S, 148°14.224´E; 3 Jul. 2013; station 119; mangrove of Rhizophora and Avicennia on one side of creek; MTQ. Color and morphology of live animals (Fig. 26) Live animals are often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, occasionally mottled with darker or lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot is gray. The hyponotum is gray (same color as the foot), yellow, or both (yellow outer ring and gray inner ring). The color of the foot and of the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are gray or brown, and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). Digestive system (Figs 27 A–B, 28) Radulae measure up to 5.4 mm in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 27 C–D, 29) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle) and the accessory penial gland (flagellum and hollow spine). The hollow spine of the accessory penial gland is narrow, elongated, slightly curved. Its base is conical. Its diameter is approximately 80 μm for most of its length, except at its base (200 μm) and tip (60 μm). Its length ranges from 2.5 mm ([1519] AM C.468917.001) to 2.7 mm ([1521] AM C.468919.001), and its shape does vary between individuals (Fig. 29). The penial sheath is narrow and elongated. The retractor muscle is short (shorter than the penial sheath) or even vestigial (its distal end being free in the visceral cavity, with no clear insertion). The deferent duct is highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, hollow tube of approximately 100 μm in diameter; internally, the penis bears a few smooth (no hooks) longitudinal ridges. Distinctive diagnostic features Externally, Paromoionchis daemelii cannot be distinguished from other species of Paromoionchis gen. nov. (Table 3). Also, its internal anatomy (accessory penial gland, vestigial penial retractor muscle, smooth penis) is very similar to that of P. boholensis gen. et sp. nov. The distribution range of P. daemelii overlaps with that of only one species of Paromoionchis gen. nov., P. tumidus (Fig. 6). Both species live in similar habitats and can even be found at the same station. They can only be distinguished internally thanks to a few anatomical details: in P. daemelii, the penis is smooth and the penial retractor muscle is very short or even vestigial, while in P. tumidus the penis bears some tiny hooks and the penial retractor muscle inserts near the heart (Table 3). Distribution (Fig. 6) Australia: New South Wales (type locality, present study), Queensland (present study). Habitat (Fig. 30) Paromoionchis daemelii is found on mud or muddy logs, inside or near mangroves, or on muddy sand. It is not common in central Queensland or New South Wales, but its abundance in southern Queensland is unknown. Remarks The publication dates of the various sections of the volume on Landmollusken by Carl Semper in the Reisen im Archipel der Philippinen series were clarified by Johnson (1969). The species name Onchidium daemelii was first published by Semper in 1880 with one figure (pl. 20, fig. 2) but no written description. Because Onchidium daemelii was published before 1931, ICZN Article 12.2.7 applies and the name is available (Semper’s figures are regarded as an indication accompanying the name Onchidium daemelii). Also, the specific name was originally spelled dämelii. However, according to ICZN Article 32.5.2.1., the correct spelling is daemelii. Both daemelii (e.g., Labbé 1934a) and damelii (e.g., Kenny & Smith 1987, 1988) are spelling mistakes. According to our current data, there are only two species of Paromoionchis gen. nov. in New South Wales (Fig. 6): P. tumidus and P. daemelii. They cannot be distinguished externally but they differ anatomically (Table 3). Both species are characterized by the lack of a rectal gland, a digestive system of type II, a male opening clearly to the left of the right eye tentacle (Semper described a male opening under the right eye tentacle, but it is distinctly below and left of it) and an accessory penial gland. The retractor muscle of the penis of O. daemelii, described as “very thin” by Semper, is vestigial in the lectotype, whereas the retractor muscle of P. tumidus is not vestigial and inserts near the heart. No “teeth” (the term he used to refer to penial hooks) are mentioned by Semper in the original description of O. daemelii, while the penis of P. tumidus bears some hooks. Therefore, the combination of characters found in the lectotype of O. daemelii and in Semper’s original description (retractor muscle vestigial and soft penis with no hooks) is only compatible with the species described here, not with P. tumidus, which justifies the present application of P. daemelii. Onchidium daemelii was recorded from New South Wales (Lendenfeld 1886; Tenison-Woods 1888) and even New Guinea (Tapparone-Canefri 1883) but it is not possible to determine whether it was identified properly without re-examining the material which these authors examined (which may or may not have been deposited). Bretnall (1919), Hoffmann (1928) and Labbé (1934a) mentioned Onchidium daemelii without adding any new material. Finally, Kenny & Smith (1987) published an ecological study on a species they identified as Onchidium damelii in a mangrove on Magnetic Island, Queensland. However, given that P. daemelii is rare in northern and central Queensland and that its identification requires detailed study of the internal anatomy, Kenny & Smith likely studied P. tumidus rather than P. daemelii (or a mix of both species).

Paromoionchis boholensis Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: 104C35EF-FBF9-4EC2-A5A8-89AC30009270 Figs 31���40 Etymology Paromoionchis boholensis gen. et sp. nov. is named after Bohol Island, where the type locality is. Material examined Holotype PHILIPPINES ��� holotype (28/18 [3288] mm); Bohol, Maribojoc; 09��43.645��N, 123��50.988��E; 15 Jul. 2014; station 193; small island at end of boardwalk, sandy mud and rocks in back of mangrove; PNM 0 41266. Other material INDONESIA ��� Sulawesi ���2spec.(35/22[2128]and37/20[2129]mm); Wori; 01��36.055��N, 124��51.730��E; 9 Mar. 2013; station 84; tall mangrove forest of Sonneratia and Avicennia, with old logs; UMIZ 0 0 141 ��� 1 spec. (9/6 [2175] mm); Bahoi; 01��43.355��N, 125��01.232��E; 10 Mar. 2013; station 85; sand, small rocks and pieces of wood, near narrow coastal mangrove; UMIZ 0 0 142 ��� 1 spec. (20/13 [2199] mm); Tamperong; 01��41.513��N, 125��00.797��E; 12 Mar. 2013; station 87; muddy mangrove with small and dense Rhizophora; UMIZ 0 0 143 ��� 1 spec. (12/8 [2316] mm); Mantehang; 01��41.880��N, 124��46.741��E; 15 Mar. 2013; station 91; Sonneratia at low intertidal and Rhizophora at high intertidal; UMIZ 0 0 144 ��� 1 spec. (20/13 [2360] mm); Panikkiang Island; 04��21.730��S, 119��35.630��E; 25 Mar. 2013; station 94; Rhizophora, Avicennia, Sonneratia and old logs; UMIZ 0 0 145. ��� Ambon ��� 3 spec. (40/25 [2849], 45/30 [2850] and 45/25 [2851] mm); Wai; 03��34.652��S, 128��19.526��E; 15 Feb. 2014; station 132; narrow band of old Avicennia trees on sandy mud, old logs on ground; UMIZ 0 0 146. ��� Seram ��� 1 spec. (45/28 [2884] mm); Piru; 03��04.072��S, 128��11.362��E; 19 Feb. 2014; station 136; Sonneratia mangrove next to fish market, next to beach of palms and ferns, with cattle roaming around; UMIZ 0 0 147. ��� Kei Islands ��� 2 spec. (10/8 [2896] and 17/8 [2901] mm); Un; 05��38.273��S, 132��45.738��E; 23 Feb. 2014; station 137; Bruguiera and Rhizophora, some muddy areas and some with coral rubble; UMIZ 0 0 148 ��� 2 spec. (15/10 [2903] and 18/8 [2911] mm); Un; 05��38.273��S, 132��45.738��E; 25 Feb. 2014; station 140; back of mangrove, on rocks, on mud, inside logs and under leaf litter; UMIZ 0 0 149 ��� 3 spec. (40/22 [3565], 30/20 [2935] and 40/22 [2937] mm); Fiditan; 05��35.957��S, 132��45.112��E; 28 Feb. 2014; station 144; rocks behind muddy Rhizophora mangrove; UMIZ 0 0 150. ��� Bali ��� 1 spec. (35/17 [3117] mm); Gilimanuk; 08��10.156��S, 114��26.652��E; 4 Apr. 2014; station 156; muddy mangrove with Rhizophora and Avicennia trees; UMIZ 0 0 140. ��� Halmahera ��� 1 spec. (25/16 [5019] mm); Sofifi; 00��45.473��N, 127��35.897��E; 8 Mar. 2015; station 205; Sonneratia mangrove, with dense roots and hard mud; UMIZ 0 0 151 ��� 2 spec. (47/30 [5140] and 35/22 [5146] mm); Gamkonora; 01��26.911��N, 127��31.625��E; 21 Mar. 2015; station 219; mostly Rhizophora mangrove with some sandy areas and some open muddy spaces; UMIZ 0 0 152. PHILIPPINES ��� Luzon ��� 1 spec. (25/18 [3609] mm); Lian, Batangas; 13��58.130��N, 120��37.471��E; 5 Jul. 2014; station 179; narrow and impacted mangrove of Avicennia near village, very sandy, little to no mud; PNM 0 41267. ��� Bohol ��� 2 spec. (16/9 [3283] and 17/10 [3619] mm); same data as for holotype; PNM 0 41268 ��� 3 spec. (20/15 [3369], 35/18 [3372] and 27/20 [3411] mm); Mabini; 09��51.586��N, 124��34.155��E; 18 Jul. 2014; station 196; open Avicennia and Sonneratia forest with sand, algae and coral rubble; PNM 0 41269 ��� 5 spec. (30/22 [3412], 30/23 [3413], 40/17 [3417], 40/20 [3422] and 42/25 [3423] mm); Maribojoc; 09��44.280��N, 123��49.389��E; 20 Jul. 2014; station 202; uplifted coral rubble with sand and algae, near Sonneratia trees; PNM 0 41270. Color and morphology of live animals (Figs 31���32) Live animals are often covered with mud, in which case their dorsal color can hardly be seen. In unit #1, the background of the dorsal notum is brown, occasionally mottled with darker or lighter areas, while in unit #2 it ranges from very light brown (almost white) to dark brown, mottled or not. In some animals, there is a reddish hue on the margin of the dorsal notum (unit #1). In addition, in most animals the tip of the dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot is orange (unit #1) or varies from gray to yellow and orange (unit #2). The hyponotum is also orange, often with a darker ring on the margin which may be bright red (unit #1) or homogenously gray, yellow, or orange, but can also display a mix of two or three of those colors (unit #2). The color of both the foot and the hyponotum of an individual can change very rapidly, especially when disturbed. The ocular tentacles are reddish brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). Digestive system (Figs 33A, 34A, 35���36) Radulae measure up to 4.5 mm (unit #1) and 4 mm (unit #2) in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 33 B���C, 34B���C, 37���38) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle) and the accessory penial gland (flagellum and hollow spine). The hollow spine of the accessory penial gland is narrow, elongated, slightly curved. Its base is conical. Its diameter is approximately 50 to 70 ��m for most of its length and 100���130 ��m at its base (unit #1) and approximately 70 to 80 ��m for most of its length and 150���200 ��m at its base (unit #2). Its length ranges from 1 mm ([3288] PNM 0 41266, holotype) to 1.2 mm ([3372] PNM 041269) in unit #1 and from 1.1 mm ([5019] UMIZ 00151) and 1.3 mm ([3117] UMIZ 00140) to 1.8 mm ([2911] UMIZ 0 0 149, [5140] UMIZ 00152) in unit #2, and its shape does vary between individuals (Fig. 38). The penial sheath is narrow and elongated. The retractor muscle is vestigial, i.e., with its distal end being free in the visceral cavity, with no clear insertion (unit #1), or absent or vestigial (unit #2). The deferent duct is highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, smooth (no hooks) and hollow tube of approximately 200 ��m in diameter. Distinctive diagnostic features Externally, the color of the foot and hyponotum can help one to identify Paromoionchis boholensis gen. et sp. nov., but unfortunately it is not fully reliable. Specimens with a bright orange foot and hyponotum are only found in P. boholensis gen. et sp. nov., especially in unit #1 but also in unit #2; the ventral side of P. tumidus, which is sympatric with P. boholensis (Fig. 6), can be orange but not bright orange. However, specimens with a more yellowish or greyish foot and hyponotum cannot be identified externally. The internal anatomy of P. boholensis gen. et sp. nov. (accessory penial gland, vestigial penial retractor muscle, penis with no hooks) is similar to that of P. daemelii. However, P. boholensis gen. et sp. nov. and P. daemelii do not overlap geographically, at least based on the present data. Thus, within its distribution range P. boholensis gen. et sp. nov. is the only species with this combination of internal characters. Indeed, the internal characters of the two species of Paromoionchis gen. nov. with which P. boholensis gen. et sp. nov. is sympatric (P. goslineri gen. et sp. nov. and P. tumidus) are different (Table 3). It must be noted that the known distribution of species of Paromoionchis gen. nov. may change as new records are found in the future and so the use of geographic data should only be used with caution for identification. Distribution (Fig. 6) Philippines (unit #1): Bohol (type locality), Luzon. Indonesia (unit #2): Ambon, Bali, Halmahera, Kei Islands, Seram, Sulawesi. Habitat (Figs 39���40) Unit #1 of Paromoionchis boholensis gen. et sp. nov. is found on sandy mud or sand with very little mud, in mangroves or near mangrove trees and is rare (it was found at only four stations). Unit #2 is found in open or dense mangroves, on soft or hard mud, as well as on muddy sand and is common (but not as common as P. tumidus unit #1)., Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 50-59, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525

Paromoionchis daemelii (Semper, 1880) comb. nov. Figs 26���30 Onchidium d��melii Semper, 1880: pl. 20, fig. 2. Onchidium d��melii ��� Semper 1882: 270���271, pl. 21, fig. 9. Material examined Type material AUSTRALIA ��� lectotype (here designated; 17/ 14 mm); New South Wales, Sydney; ZMB 31640 a ��� 1 paralectotype (17/ 17 mm); same locality as lectotype; ZMB 31640 b ��� 1 paralectotype (destroyed, dried); same locality as lectotype; ZMB 39035 ��� 2 paralectotypes (?); same locality as lectotype; ZMH 27476 /2. Notes on type material The lectotype, 17/ 14 mm, is designated here (ZMB 31640 a). All other syntypes become paralectotypes. According to the original description, the type material included only three specimens. However, five possible syntypes could be located in museum collections, all from Sydney, Australia: 2 specimens, one of which, dissected with male parts remaining inside (17/ 14 mm), is designated as lectotype (ZMB 31640 a) and the other one, still entire (17/ 17 mm), is a paralectotype (ZMB 31640 b); 1 specimen destroyed, in pieces and completely dried (ZMB 39035); and 2 specimens (ZMH 27476 /2), both entire. It is unclear exactly which specimens Semper used for the description, but it is safe to assume that the anatomical details he provided are based on the only two dissected specimens. Two species of Paromoionchis gen. nov. are present in Sydney, P. tumidus and the species described here, which are cryptic externally but distinct internally. Thus, the specimens that were not dissected by Semper could belong either to P. tumidus or to the species treated here. Hence the necessity of designating a lectotype in order to clarify the application of the name Onchidium daemelii. Other material AUSTRALIA ��� New South Wales ��� 1 spec. (37/25 [1511] mm); Sydney, Middle Harbour, N of Roseville Bridge, W bank; 33��46.332��S, 151��12.106��E; 23 Nov. 2011; station 38; open mangrove, in old logs on the mud; AM C.468910.001 ��� 1 spec. (17/10 [1510] mm); same data as for preceding; AM C.468911.001 ��� 1 spec. (65/35 [1518] mm); Sydney, Pittwater, Church Point, next to yacht club; 33��39.107��S, 151��17.363��E; 24 Nov. 2011; station 39; muddy sand next to small patch of mangrove and rocks on sandy beach; AM C.468913.001 ��� 1 spec. (60/35 [1519] mm); same data as for preceding; AM C.468917.001 ��� 1 spec. (28/18 [1515] mm); same data as for preceding; AM C.468914.001 ��� 1 spec. (52/28 [1514] mm); same data as for preceding; AM C.468912.002 ��� 1 spec. (40/20 [1512] mm); same data as for preceding; AM C.468912.003 ��� 1 spec. (50/25 [1521] mm); Sydney, Pittwater, Careel Bay; 33��37.323��S, 151��19.878��E; 24 Nov. 2011; station 40; supratidal zone on the margin of salt marsh, mangrove patch on side of creek; AM C.468919.001. ��� Queensland ��� 2 spec. (15/12 [1532] and 8/6 [1533] mm); Thirsty Sound, Plum Tree, beach in front of Endeavour Park; 22��08.144��S, 150��01.856��E; 14 Sep. 2002; I. Loch, D.L. Beechey and A.C. Miller leg.; sheltered, muddy cobble shore; AM C.415270 ��� 1 spec. (8/6 [2668] mm); Bowen, Doughty Creek; 20��01.478��S, 148��14.224��E; 3 Jul. 2013; station 119; mangrove of Rhizophora and Avicennia on one side of creek; MTQ. Color and morphology of live animals (Fig. 26) Live animals are often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, occasionally mottled with darker or lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot is gray. The hyponotum is gray (same color as the foot), yellow, or both (yellow outer ring and gray inner ring). The color of the foot and of the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are gray or brown, and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few millimeters long). Digestive system (Figs 27 A���B, 28) Radulae measure up to 5.4 mm in length. Examples of radular formulae are presented in Table 4. Reproductive system (Figs 27 C���D, 29) The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle) and the accessory penial gland (flagellum and hollow spine). The hollow spine of the accessory penial gland is narrow, elongated, slightly curved. Its base is conical. Its diameter is approximately 80 ��m for most of its length, except at its base (200 ��m) and tip (60 ��m). Its length ranges from 2.5 mm ([1519] AM C.468917.001) to 2.7 mm ([1521] AM C.468919.001), and its shape does vary between individuals (Fig. 29). The penial sheath is narrow and elongated. The retractor muscle is short (shorter than the penial sheath) or even vestigial (its distal end being free in the visceral cavity, with no clear insertion). The deferent duct is highly convoluted, with many loops. Inside the penial sheath, the penis is a narrow, elongated, soft, hollow tube of approximately 100 ��m in diameter; internally, the penis bears a few smooth (no hooks) longitudinal ridges. Distinctive diagnostic features Externally, Paromoionchis daemelii cannot be distinguished from other species of Paromoionchis gen. nov. (Table 3). Also, its internal anatomy (accessory penial gland, vestigial penial retractor muscle, smooth penis) is very similar to that of P. boholensis gen. et sp. nov. The distribution range of P. daemelii overlaps with that of only one species of Paromoionchis gen. nov., P. tumidus (Fig. 6). Both species live in similar habitats and can even be found at the same station. They can only be distinguished internally thanks to a few anatomical details: in P. daemelii, the penis is smooth and the penial retractor muscle is very short or even vestigial, while in P. tumidus the penis bears some tiny hooks and the penial retractor muscle inserts near the heart (Table 3). Distribution (Fig. 6) Australia: New South Wales (type locality, present study), Queensland (present study). Habitat (Fig. 30) Paromoionchis daemelii is found on mud or muddy logs, inside or near mangroves, or on muddy sand. It is not common in central Queensland or New South Wales, but its abundance in southern Queensland is unknown. Remarks The publication dates of the various sections of the volume on Landmollusken by Carl Semper in the Reisen im Archipel der Philippinen series were clarified by Johnson (1969). The species name Onchidium daemelii was first published by Semper in 1880 with one figure (pl. 20, fig. 2) but no written description. Because Onchidium daemelii was published before 1931, ICZN Article 12.2.7 applies and the name is available (Semper���s figures are regarded as an indication accompanying the name Onchidium daemelii). Also, the specific name was originally spelled d��melii. However, according to ICZN Article 32.5.2.1., the correct spelling is daemelii. Both daemelii (e.g., Labb�� 1934a) and damelii (e.g., Kenny & Smith 1987, 1988) are spelling mistakes. According to our current data, there are only two species of Paromoionchis gen. nov. in New South Wales (Fig. 6): P. tumidus and P. daemelii. They cannot be distinguished externally but they differ anatomically (Table 3). Both species are characterized by the lack of a rectal gland, a digestive system of type II, a male opening clearly to the left of the right eye tentacle (Semper described a male opening under the right eye tentacle, but it is distinctly below and left of it) and an accessory penial gland. The retractor muscle of the penis of O. daemelii, described as ���very thin��� by Semper, is vestigial in the lectotype, whereas the retractor muscle of P. tumidus is not vestigial and inserts near the heart. No ���teeth��� (the term he used to refer to penial hooks) are mentioned by Semper in the original description of O. daemelii, while the penis of P. tumidus bears some hooks. Therefore, the combination of characters found in the lectotype of O. daemelii and in Semper���s original description (retractor muscle vestigial and soft penis with no hooks) is only compatible with the species described here, not with P. tumidus, which justifies the present application of P. daemelii. Onchidium daemelii was recorded from New South Wales (Lendenfeld 1886; Tenison-Woods 1888) and even New Guinea (Tapparone-Canefri 1883) but it is not possible to determine whether it was identified properly without re-examining the material which these authors examined (which may or may not have been deposited). Bretnall (1919), Hoffmann (1928) and Labb�� (1934a) mentioned Onchidium daemelii without adding any new material. Finally, Kenny & Smith (1987) published an ecological study on a species they identified as Onchidium damelii in a mangrove on Magnetic Island, Queensland. However, given that P. daemelii is rare in northern and central Queensland and that its identification requires detailed study of the internal anatomy, Kenny & Smith likely studied P. tumidus rather than P. daemelii (or a mix of both species)., Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 44-50, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525, {"references":["Semper C. 1880 - 1885. Dritte Familie, Onchidiidae. In: Semper C. (ed.) Reisen im Archipel der Philippinen. Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken: 251 - 264 [1880],","Johnson R. I. 1969. Semper's Reisen im Archipel der Philippinen, wissenschaftliche Resultate, 1867 - 1916. A complete collation. Journal of the Society for the Bibliography of Natural History 5: 144 - 147. https: // doi. org / 10.3366 / jsbnh. 1969.5.2.144","Labbe A. 1934 a. Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues. Annales de l'Institut oceanographique 14: 173 - 246.","Kenny R. & Smith A. 1987. Distribution of Onchidium damelii Semper (Gastropoda, Onchidiidae). Pacific Science 41: 21 - 30.","Kenny R. & Smith A. 1988. Emergence behaviour of Onchidium damelii Semper, 1882 (Gastropoda, Onchidiidae). Journal of the Malacological Society of Australia 9: 19 - 20. https: // doi. org / 10.1080 / 00852988.1988.10673996","Lendenfeld R. von. 1886. Preliminary report on the histological structure of the dorsal papillae of certain species of Onchidium. Proceedings of the Linnean Society of New South Wales 10: 730 - 732. https: // doi. org / 10.5962 / bhl. part. 17961","Tenison-Woods J. E. 1888. On the anatomy and life history of Mollusca peculiar to Australia. Journal and Proceedings of the Royal Society of New South Wales 22: 106 - 187. Available from https: // biodiversitylibrary. org / page / 41841920 [accessed 22 Dec. 2018].","Tapparone-Canefri C. 1883. Fauna malacologica delle Nuova Guinea e delle isole adiacenti. Annali del Museo Civico di Storia Naturale di Genova 19: 1 - 313. Available from https: // biodiversitylibrary. org / page / 10812600 [accessed 22 Dec. 2018].","Bretnall W. 1919. Onchidiidae from Australia and the South-Western Pacific Islands. Records of the Australian Museum 12: 303 - 328. https: // doi. org / 10.3853 / j. 0067 - 1975.12.1919.888","Hoffmann K. 1928. Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher, Jena 55: 29 - 118."]}

Paromoionchis penangensis Dayrat & Goulding gen. et sp. nov. urn:lsid:zoobank.org:act: 840ABD3E-61AC-4B1E-9D83-B15A8099F0BA Figs 41���44 Etymology Paromoionchis penangensis gen. et sp. nov. is named after Penang Island, Malaysia, in the Strait of Malacca, which is the type locality. Material examined Holotype MALAYSIA ��� holotype (26/14 [6037] mm); Peninsular Malaysia, Penang, Pantai Acheh; 05��24.922��N, 100��11.571��E; 1 Aug. 2016; station 261; Avicennia mangrove, with both very soft mud and hard mud; USMMC 00059. Other material INDIA ��� Andaman Islands ��� 1 spec. (18/10 [1086] mm); Middle Andaman, Rangat, Yerrata, Saban; 12��27.451��N, 092��53.792��E; 10 Jan. 2011; station 56; open, impacted mangrove patch by a creek, near village, with medium trees and old logs; BNHS 92 ��� 2 spec. (18/8 [1100] and 9/6 [1101] mm); Middle Andaman, Rangat, Shyamkund; 12��28.953��N, 092��50.638��E; 11 Jan. 2011; station 57; by a large river, deep mangrove with tall trees, small creeks and plenty of old logs, next to a road and a small cemented bridge over a creek; BNHS 53 ��� 2 spec. (20/10 [1117] and 22/12 [1118] mm); Middle Andaman, Shantipur, Kadamtala; 12��19.843��N, 092��46.377��E; 12 Jan. 2011; station 58; open area with hard mud and many old logs, next to a mangrove with medium trees; BNHS 11 ��� 2 spec. (30/15 [1129] and 12/7 [1130] mm); South Andaman, Bamboo Flat, Shoal Bay; 11��47.531��N, 092��42.577��E; 13 Jan. 2011; station 59; open mangrove with medium trees, hard mud, dead logs, next to a road and a small cemented bridge for creek; BNHS 4. ��� Maharashtra ��� 1 spec. (35/20 [1167] mm); Watad; 17��15.791��N, 73��17.623��E; 23 Dec. 2011; station 46; Avicennia mangrove, by field, with deep and very watery mud; BNHS 46 ��� 3 spec. (30/18 [1177], 20/14 [1175] and 15/10 [1173] mm); same data as for preceding; BNHS 98 ��� 2 spec. (16/11 [1176] and 27/21 [1182] mm); Aare Ware; 17��04.404��N, 73��17.747��E; 24 Dec. 2011; station 47; mangrove with soft mud and some areas with pools, mostly Avicennia with a few small Rhizophora; BNHS 42. MALAYSIA ��� Peninsular Malaysia ��� 2 spec. (30/20 [5990] and 30/20 [5991] mm); Kuala Gula; 04��55.991��N, 100��26.917��E; 29 Jul. 2016; station 259; mostly Avicennia, a few Bruguiera and Rhizophora, along a creek, both soft and hard mud; USMMC 0 0 0 60 ��� 2 spec. (20/14 [957] and 15/10 [958] mm); Nibong Tebal, Pulau Burung; 05��12.488��N, 100��25.564��E; 11 Jul. 2011; station 17; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 61 ��� 1 spec. (48/35 [6020] mm); Nibong Tebal, Pulau Burung; 05��12.488��N, 100��25.564��E; 30 Jul. 2016; station 260; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 62 ��� 3 spec. (25/12 [6031], 25/18 [6033] and 25/16 [6039] mm); same data as for holotype; USMMC 0 0 0 63. Color and morphology of live animals (Fig. 41) Live animals are most often covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, occasionally mottled with darker or lighter areas. In addition, in some animals, the tip of dorsal papillae (with and without dorsal eyes) can be yellow. The foot is gray, occasionally with a light yellow hue. The hyponotum is uniform gray or gray (inner ring) and yellow (outer ring). The color of both the foot and the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are brown and may or may not be speckled with white dots, like the head. The ocular tentacles are short (just a few mm long). Digestive system (Figs 42A, 43) Radulae measure up to 3.2 mm in length. Examples of radular formulae are presented in Table 4. Reproductive system (Fig. 42 B���C) In the posterior (female) organs, the distal portion of the oviduct and of the duct to the spermatheca is wider than in other species, which makes sense given the wide penis. The male anterior organs consist of the penial complex (penis, penial sheath, vestibule, deferent duct, retractor muscle). An accessory penial gland is absent. The penial sheath is large (at least ten times as large as the deferent duct). The retractor muscle is strong, long and inserts near the heart. The deferent duct is convoluted, with many loops. Inside the penial sheath, the penis is a large (wider than long), smooth (no hooks), muscular mass. Distinctive diagnostic features Externally, Paromoionchis penangensis gen. et sp. nov. cannot be reliably distinguished from other species of Paromoionchis gen. nov. Its distribution only overlaps with that of P. tumidus. Our data suggest that the tips of the dorsal papillae of P. penangensis gen. et sp. nov. tend to be paler yellow, while they tend to be brighter yellow in P. tumidus. However, the internal anatomy of P. penangensis gen. et sp. nov., especially the large penis inside the large penial sheath, is very distinct from that of all other species and reliably distinguishes it from P. tumidus. Distribution (Fig. 6) Malaysia: Peninsular Malaysia, Strait of Malacca (type locality). India: Andaman Islands (Bay of Bengal), Maharashtra (W coast of India). Habitat (Fig. 44) Paromoionchis penangensis gen. et sp. nov. is found on soft and hard mud, in mangroves or in open areas near mangroves. This species was only found at three stations in the Strait of Malacca, three stations in the Andaman Islands (Bay of Bengal), and three stations in Maharashtra (W coast of India). However, at each station it was found to be quite abundant., Published as part of Dayrat, Beno��t, Goulding, Tricia C., Khalil, Munawar, Apte, Deepak, Bourke, Adam J., Comendador, Joseph & Tan, Shau Hwai, 2019, A new genus and three new species of mangrove slugs from the Indo-West Pacific (Mollusca: Gastropoda: Euthyneura: Onchidiidae), pp. 1-77 in European Journal of Taxonomy 500 on pages 59-64, DOI: 10.5852/ejt.2019.500, http://zenodo.org/record/2577525

Paromoionchis tumidus (Semper, 1880) comb. nov. Figs 7 –25 Onchidium tumidum Semper, 1880: 262 –263, pl. 20, figs 3–4, pl. 23, fig. 4. Onchidium samarense Semper, 1880: 268 –269, pl. 20, figs 9, 13, pl. 23, fig. 7. Syn. nov. Onchidium mertoni Simroth, 1918: 294 –296, pl. XX, figs 43–47. Syn. nov. Onchidium hongkongense Britton, 1984: 188 –190, figs 6–7. Syn. nov. Onchidium samarense – Semper 1882: 268–269, pl. 21, fig. 5. Material examined Type material SINGAPORE • lectotype (here designated; 28/ 22 mm); ZMB 39019 a • 15 paralectotypes; ZMB 39019 b • 2 paralectotypes; NHMD 300305 • 1 paralectotype; SMF 333603 /1. AUSTRALIA • 2 paralectotypes; Queensland, Mackay; ZMB 39020. Other type material PHILIPPINES • lectotype of Onchidium samarense (here designated; 22/ 17 mm); Samar Island, Palapa harbor; ZMB 39025 a • 2 paralectotypes of O. samarense (24/20 and 20/ 15 mm); same locality as lectotype; ZMB 39025 b. INDONESIA • lectotype of Onchidium mertoni (here designated; 15/ 9 mm); Aru Islands, Kobroor, Sungai; 5 Jan. 1908; ZMB 121591 a • 4 paralectotypes of O. mertoni (14/8, 14/10, 15/14 and 14/ 10 mm); same data as for lectotype; ZMB 121591 b. CHINA • holotype of Onchidium hongkongense (17/ 13 mm); Hong Kong; NHM 1982290 • 15 paratypes; same locality as holotype; NHM 1982291 to 1982292. Notes on type material Onchidium tumidum. Lectotype, 28/ 22 mm, designated here (ZMB 39019 a). All other syntypes become paralectotypes (the 15 paralectotypes from the same lot are now ZMB 39019 b). According to the original description, the type material included 42 specimens from Singapore and an unknown number of specimens from Port Mackay, Queensland, Australia. A total of 21 syntypes were located in museum collections: 19 specimens from Singapore (16 specimens, ZMB 39019; 2 specimens, NHMD 300305; 1 specimen, SMF 333603 /1) and 2 specimens from Mackay (ZMB 39020). There also are two possible syntypes from Australia (ZMH 27480 /2). Two similar species of Paromoionchis gen. nov. are found at Port Mackay, P. tumidus and P. daemelii, which anatomically can only be distinguished based on the insertion of the retractor muscle of the penis. In the lectotype designated here from Singapore, the retractor muscle inserts near the heart, exactly as in the species described here. However, in one of the two paralectotypes of P. tumidus from Mackay (ZMB 39020), the retractor muscle is vestigial, as in P. daemelii (in the other paralectotype from Mackay, the male apparatus was destroyed prior to the present investigation and could not be examined). Hence, it was necessary to designate a lectotype from Singapore in order to clarify the application of P. tumidus. Note that the type material was fixed in formalin more than 130 years ago and no DNA sequencing could be attempted. Onchidium samarense. Lectotype, 22/ 17 mm, designated here (ZMB 39025 a). The two other syntypes become paralectotypes (ZMB 39025 b). According to the original description, the type material included only two specimens from the same locality in Samar, Philippines. However, the jar with the type material currently contains three similar-looking specimens (syntypes), all of which were dissected prior to the present study. It is not excluded that the original description was based on only two of those three specimens but it is also possible that Semper himself identified all three specimens as O. samerense [sic] (with a minor typo in the original description). The lectotype still contains all its internal organs, including the male copulatory parts. One paralectotype (24/ 20 mm) is mostly destroyed, with no internal organs left except the digestive gland (a few destroyed pieces of organs are in a vial). The other paralectotype (20/ 15 mm) still contains internal organs, but the male parts are missing. Our observations and comments are mostly based on the only specimen with male parts; hence its designation as a lectotype. Note that the type material was fixed in formalin more than 130 years ago and no DNA sequencing could be attempted. Note also that if, in the future, Onchidium samarense were to be regarded as a valid species name in Paromoionchis gen. nov., the specific name samarense (neuter) would need to become samarensis (masculine). Onchidium mertoni. Lectotype, 15/ 9 mm, designated here (ZMB 121591 a). The four other syntypes become paralectotypes (ZMB 121591 b). Simroth mentioned in the original description that all five specimens were very hard. Indeed, it seems that they dried out at some point and they are very poorly preserved. The lectotype designated here is the only specimen that is complete. It was partially dissected for the present study (the penial hooks, identical to those of O. tumidum, are illustrated here). Two paralectotypes (14/8 and 14/ 10 mm) were dissected prior to the present study and are completely empty. Two other paralectotypes (15/14 and 14/ 10 mm) are in very poor condition (the body is extremely hard and the digestive system is partly outside the body through the foot). A lectotype is designated here to clarify the application of the name O. mertoni because several species of Paromoionchis gen. nov. are potentially sympatric in the Aru Islands and so it cannot be excluded that the five original syntypes belong to different species. Note that the type material was fixed in formalin more than 100 years ago and no DNA sequencing could be attempted. Onchidium hongkongense. Holotype, 17/ 13 mm, by original designation (NHM 1982290) and 15 paratypes (NHM 1982291, NHM 1982292). The holotype is largely destroyed due to prior dissection, likely by Britton. Large parts of the notum and of the reproductive organs are missing. Even though it is mostly destroyed, the digestive system is confirmed to be of type II. A few paratypes were checked for the present study and their anatomy matches that of the holotype. Note that the type material was fixed in formalin more than 40 years ago and no DNA sequencing could be attempted. Note also that the specific name hongkongensis (masculine or feminine gender) originally used by Britton is corrected to hongkongense (neuter) for gender agreement with Onchidium. Should Onchidium hongkongense ever become a valid species name in Paromoionchis gen. nov., hongkongense would then need to be changed back to hongkongensis. Other material AUSTRALIA – New South Wales • 1 spec. (20/15 [1522] mm); Sydney, Pittwater, Careel Bay; 33°37.323´S, 151°19.878´E; 24 Nov. 2011; station 40; supratidal zone on margin of salt marsh, mangrove patch on side of creek; AM C.468918.005 • 1 spec. (35/20 [1529] mm); Sydney, Hawkesbury River, Cheero Point; 33°30.687´S, 151°11.669´E; 25 Nov. 2011; station 42; open mangrove with old logs; AM C.468924.001 • 1 spec. (33/20 [1528] mm); same data as for preceding; AM C.468923.002 • 1 spec. (32/20 [1530] mm); same data as for preceding; AM C.468925.001. – Northern Territory • 1 spec. (45/32 [1634] mm); Darwin, near Channel Island Road; 12°34.979´S, 130°55.992´E; 16 Aug. 2012; station 65; sequence of Sonneratia, Rhizophora and Ceriops; NTM P.57620 • 1 spec. (40/25 [1686] mm); Darwin, end of Channel Island Road; 12°33.557´S, 130°52.894´E; 17 Aug. 2012; station 66; sequence of Sonneratia, Rhizophora and Ceriops; NTM P.57621 • 1 spec. (42/38 [1638] mm); same data as for preceding; NTM P.57623 • 2 spec. (30/17 [1705] and 17/12 [1645] mm); Darwin, close to Tiger Brenan Road (small service road); 12°28.782´S, 130°54.750´E; 19 Aug. 2012; station 69; high tidal Ceriops; NTM P.57622 • 1 spec. (36/22 [1651] mm); Darwin, Elizabeth Road; 12°32.893´S, 130°57.642´E; 20 Aug. 2012; station 70; Ceriops and old logs in Rhizophora forest; NTM P.57624. – Queensland • 1 spec. (45/30 [2562] mm); Cairns, Yorkey’s Knob; 16°48.558´S, 145°42.768´E; 17 Jun. 2013; station 101; hard, red mud with grasses; MTQ • 1 spec. (45/30 [2602] mm); Townsville, Magnetic Island; 19°09.938´S, 146°49.029´E; 24 Jun. 2013; station 109; water on the mud; MTQ • 1 spec. (15/10 [2627] mm); Bowen; 20°00.658´S, 148°15.878´E; 1 Jul. 2013; station 115; back of mangrove across from beach, dense Rhizophora, Avicennia trees with soft mud around; MTQ • 1 spec. (55/30 [2637] mm); Bowen; 20°00.913´S, 148°15.745´E; 1 Jul. 2013; station 116; mangrove away from ocean, small area of open Avicennia mangrove, surrounded by Rhizophora; MTQ • 1 spec. (20/10 [2652] mm); Bowen, Doughty Creek; 20°01.264´S, 148°14.345´E; 2 Jul. 2013; station 117; narrow Avicennia and Rhizophora mangrove, by creek, some muddy areas and some very sandy; MTQ • 1 spec. (35/20 [2657] mm); Bowen; 20°01.478´S, 148°14.224´E; 3 Jul. 2013; station 119; Rhizophora and Avicennia mangrove; MTQ • 1 spec. (30/20 [2701] mm); Mackay; 20°08.511´S, 149°12.076´E; 8 Jul. 2013; station 125; large, dense and sandy mangrove and, by side of river, small strip of mud with Avicennia and Rhizophora; MTQ • 1 spec. (30/25 [1531] mm); Thirsty Sound, Plum Tree, beach in front of Endeavour Park; 22°08.144´S, 150°01.856´E; 14 Sep. 2002; I. Loch, D.L. Beechey and A.C. Miller leg.; sheltered, muddy cobble shore; AM C.575588. BRUNEI DARUSSALAM • 3 spec. (55/30 [1036], 35/20 [1035] and 20/15 [1062] mm); Pulau Pyatan, Teluk Brunei; 04°55.246´N, 115°02.764´E; 27 Jul. 2011; station 32; open Avicennia and Rhizophora mangrove, with hard mud; BDMNH. INDIA • 1 spec. (26/17 [1119] mm); Andaman Islands, Middle Andaman, Shantipur, Kadamtala; 12°19.843´N, 092°46.377´E; 12 Jan. 2011; station 58; open area with hard mud and many old logs, next to a mangrove with medium trees; BNHS 88. INDONESIA – Sumatra • 1 spec. (24/15 [1732] mm); Kualapenet; 05°16.275´S, 105°51.287´E; 17 Oct. 2012; station 77; narrow band of mangrove between ocean and fish ponds; UMIZ 0 0 121 • 2 spec. (35/20 [1754] and 26/16 [1755] mm); Bakauheni; 05°50.560´S, 105°46.200´E; 21 Oct. 2012; station 81; small mangrove, not far from road and next to large harbor, very impacted mangrove; UMIZ 0 0 122 • 1 spec. (38/30 [1794] mm); same data as for preceding; UMIZ 0 0 138 • 1 spec. (20/12 [1798] mm); S of Bandar Lampung; 05°32.66´S, 105°15.113´E; 28 Oct. 2012; station 83; high intertidal, fairly dense roots with some Avicennia and Nypa, edge of mangrove by road; UMIZ 0 0 123. – Sulawesi • 2 spec. (25/15 [2200] and 20/12 [2201] mm); Tamperong; 01°41.513´N, 125°00.797´E; 12 Mar. 2013; station 87; muddy mangrove with small Rhizophora in dense patches; UMIZ 0 0 124 • 1 spec. (27/15 [2240] mm); Sondaken; 01°21.777´N, 124°32.594´E; 13 Mar. 2013; station 89; sand, small rocks, pieces of wood outside narrow coastal mangrove of mostly Rhizophora; UMIZ 0 0 125 • 1 spec. (30/20 [2345] mm); Makassar, Tallo mangrove; 05°06.117´S, 119°26.777´E; 21 Mar. 2013; station 92; small mangrove used as outhouse by village, very impacted with trash; UMIZ 0 0 126 • 1 spec. (20/13 [2355] mm); Barru; 04°25.437´S, 119°35.953´E; 22 Mar. 2013; station 93; forest of mostly Avicennia and Rhizophora, with hard and sandy mud; UMIZ 0 0 127. – Ambon • 1 spec. (25/15 [3541] mm); Lateri; 03°38.261´S, 128°14.716´E; 12 Feb. 2014; station 128; mudflat next to small creek in low intertidal of mangrove preserve; UMIZ 0 0 128 • 3 spec. (45/30 [2832], 22/12 [2839] and 35/22 [2840] mm); Lateri; 03°38.237´S, 128°14.783´E; 14 Feb. 2014; station 131; muddy mangrove with Rhizophora; UMIZ 0 0 129. – Seram • 2 spec. (20/15 [2874] and 30/15 [2875] mm); Kawa; 02°58.240´S, 128°07.066´E; 18 Feb. 2014; station 135; mud next to a seawall adjacent to a mangrove; UMIZ 0 0 130. – Lombok • 2 spec. (30/20 [2950] and 20/12 [2952] mm); Tanjung Batu village; 08°45.748´S, 116°02.892´E; 24 Mar. 2014; station 145; Avicennia forest; UMIZ 0 0 131 • 1 spec. (20/14 [2961] mm); Seriwe Bay; 08°51.960´S, 116°32.838´E; 25 Mar. 2014; station 146; Avicennia mangrove with hard mud and rocks; UMIZ 0 0 132 • 1 spec. (18/10 [2960] mm); same data as for preceding; UMIZ 0 0 139. – Bali • 1 spec. (25/14 [3051] mm); Denpasar; 08°47.435´S, 115°13.197´E; 1 Apr. 2014; station 153; large mangrove by road, very soft mud; UMIZ 0 0 133 • 1 spec. (30/20 [3070] mm); Denpasar; 08°46.126´S, 115°10.803´E; 2 Apr. 2014; station 154; large mangrove by road, with shallow mud; UMIZ 0 0 134. – Halmahera • 1 spec. (25/15 [5082] mm); Akelamo; 01°01.329´N, 127°39.091´E; 10 Mar. 2015; station 207; sandymuddy beach at margin of mangrove near village; UMIZ 0 0 135 • 2 spec. (50/35 [5102] and 55/35 [5103] mm); Buli; 00°55.446´N, 128°20.612´E; 16 Mar. 2015; station 212; logged area in front of old Rhizophora forest, by the road; UMIZ 0 0 136 • 1 spec. (55/30 [5042] mm); Buli; 00°55.367´N, 128°20.647´E; 17 Mar. 2015; station 213; tall and old Rhizophora forests, high intertidal; UMIZ 0 0 137. JAPAN • 1 spec. (22/10 [3761] mm); Ehime Prefecture, Misho Bay; 32°57.634´N, 132°33.205´E; 4 Aug. 2014; station o28; mudflats; NSMT Mo 78984. MALAYSIA • 1 spec. (40/25 [963] mm); Peninsular Malaysia, Nibong Tebal, Pulau Burung; 05°12.488´N, 100°25.564´E; 11 Jul. 2011; station 17; soft mud, open mangrove of Rhizophora, with a few Sonneratia; USMMC 0 0 0 57 • 1 spec. (18/12 [928] mm); E Peninsular Malaysia, Balok; 03°53.219´N, 103°21.978´E; 14 Jul. 2011; station 19; mostly Rhizophora, with some Avicennia, hard mud with shallow pools, patches of soft mud; USMMC 0 0 0 58. PAPUA NEW GUINEA • 1 spec. (18/14 [5432] mm); Madang, Meiro River, near airport; 05°12.2´S, 145°47.4´E; 5 Nov. 2012; MNHN expedition Papua Niugini leg.; station PM01; Nypa palm swamp; MNHN IM-2013-10478 • 1 spec. (17/12 [5433] mm); same data as for preceding; MNHN IM-2013- 10479. PHILIPPINES – Luzon • 1 spec. (26/18 [3610] mm); Lian, Batangas; 13°58.130´N, 120°37.471´E; 5 Jul. 2014; station 179; narrow and impacted mangrove of Avicennia near village, very sandy, little to no mud; PNM 0 41261 • 2 spec. (30/20 [3171] and 25/15 [3192] mm); Nasugbu, Batangas; 14°10.714´N, 120°36.817´E; 6 Jul. 2014; station 182; near village, well-preserved and dense forest of Avicennia and Rhizophora; PNM 0 41255 • 1 spec. (22/14 [3172] mm); same data as for preceding; PNM 0 41262 • 2 spec. (30/20 [3200] and 35/22 [3205] mm); Calantagan, Batangas; 13°55.319´N, 120°37.260´E; 7 Jul. 2014; station 183; rocks next to Avicennia and Rhizophora forest; PNM 0 41256 • 1 spec. (30/18 [3202] mm); same data as for preceding; PNM 0 41263 • 1 spec. (35/22 [3222] mm); Calantagan, Batangas; 13°53.278´N, 120°37.124´E; 8 Jul. 2014; station 184; narrow forest on the shore, Avicennia and young Rhizophora; PNM 0 41257 • 1 spec. (33/15 [3229] mm); same data as for preceding; PNM 0 41264 • 1 spec. (27/18 [3237] mm); Calantagan, Batangas; 13°51.264´N, 120°37.383´E; 8 Jul. 2014; station 185; next to village, impacted, narrow Avicennia mangrove by the shore; PNM 0 41265. – Bohol • 1 spec. (40/25 [3344] mm); Mabini; 09°51.532´N, 124°31.685´E; 17 Jul. 2014; station 194; narrow mangrove on edge of fish ponds, tall Rhizophora and Avicennia trees, many old logs; PNM 0 41258 • 1 spec. (26/15 [3371] mm); Mabini; 09°51.586´N, 124°34.155´E; 18 Jul. 2014; station 196; Avicennia and Sonneratia open forest with sand, algae and coral rubble; PNM 0 41259 • 1 spec. (30/18 [3416] mm); Maribojoc; 09°44.280´N, 123°49.389´E; 20 Jul. 2014; station 202; uplifted coral rubble with sand and algae, near Sonneratia trees; PNM 0 41260. VIETNAM • 2 spec. (45/30 [5619] and 40/30 [5682] mm); Nha Trang; 12°12.778´N, 109°09.572´E; 27 Jul. 2015; station 237; small strip of mud with a few Rhizophora trees next to a small river, by fish ponds and houses; ITBZC IM 0 0 0 19 • 1 spec. (25/15 [5642] mm); Nha Trang; 12°24.168´N, 109°10.058´E; 29 Jul. 2015; station 239; mostly Avicennia and some small Rhizophora, with shallow mud; ITBZC IM 0 0 0 20. Color and morphology of live animals (Figs 7–10) Live animals of units #1 and #2 are often abundantly covered with mud, in which case their dorsal color can hardly be seen. The background of the dorsal notum is brown, light to dark. That background can be homogenous or clearly mottled with darker or lighter areas and, occasionally, also with red areas. In addition, in some animals the tip of the dorsal papillae (with and without dorsal eyes) can be bright yellow. The foot varies from gray (light or dark) to yellow or orange. The hyponotum is almost always yellow, from pale yellow to bright yellow and even orange. This variable yellow component can cover the entire hyponotum or just an outer ring (the inner ring being light to dark gray). The color of the foot and of the hyponotum of an individual can change rapidly, especially when disturbed. The ocular tentacles are brown (variable from light to dark) and may or may not be speckled with tiny white dots, exactly like the head. The ocular tentacles are short (just a few millimeters long). No live pictures were available for unit #3, so the following description is based on preserved specimens (Fig. 10). It is possible that bright colors (yellow, orange) were lost during preservation on both the ventral and dorsal sides. The background of the dorsal notum is brown, mottled with darker or lighter areas. The foot is light gray. The hyponotum is gray-brown, with a reddish hue on the margin (which could possibly be orange in live animals). The color of the ocular tentacles (retracted, likely short) cannot be determined. Generally speaking, the dorsal notum of any given live animal can rapidly change from almost perfectly smooth to covered by many papillae. However, when animals are not disturbed, the dorsum is usually covered by papillae of various sizes. In some animals, larger papillae may be arranged in two longitudi

Dayrat, Benoît, Goulding, Tricia C., Bourke, Adam J., Khalil, Munawar, Tan, Shau Hwai (2019): New species and new records of Melayonchis slugs (Gastropoda: Euthyneura: Pulmonata: Onchidiidae). Raffles Bulletin of Zoology 67: 557-585, DOI: 10.26107/RBZ-2019-0043

Dayrat, Benoît, Goulding, Tricia C., Khalil, Munawar, Lozouet, Pierre, Tan, Shau Hwai (2018): Systematic revision one clade at a time: A new genus of onchidiid slugs from the Indo-West Pacific (Gastropoda: Euthyneura: Pulmonata). Raffles Bulletin of Zoology 66: 814-837, DOI: http://doi.org/10.5281/zenodo.5364602, {"references":["Adams H & Adams A (1854-1858) The Genera of Recent Mollusca. J. van Voorst, London, 3 vols [vol. 1: xl + 484 pp.; vol. 2: 661 pp.; vol. 3: 138 pls.; collation in vol. 2: 661].","Audouin V & Milne-Edwards H (1832-1834) Recherches pour servir a l'histoire naturelle du littoral de la France. Crochard, Paris, 2 vols [vol. 1: 406 pp.; vol. 2: 290 pp., 8 pls.].","Baker HB (1938) Nomenclature of Onchidiidae. The Nautilus, 51: 85-88.","Blainville HMD de (1824) Mollusques. In: Cuvier F (ed.) Dictionnaire des sciences naturelles, Volume 32. FG Levrault, Strasbourg. Pp. 1-392.","Bretnall W (1919) Onchidiidae from Australia and the South- Western Pacific Islands. Records of the Australian Museum, 12: 303-328.","Buchannan F (1800) An account of the Onchidium, a new genus of the class of vermes, found in Bengal. Transactions of the Linnean Society of London, 5: 132-134.","Colgan DJ, Ponder WF & Eggler PE (2000) Gastropod evolutionary rates and phylogenetic relationships assessed using partial 28S rDNA and histone H3 sequences. Zoologica Scripta, 29: 29-63.","Cretella M (2010) The complete collation and dating of the section Zoologie of the Coquille voyage. Bollettino Malacologico, 46: 83-103.","Dall WH (1885) Notes on some Floridian land and fresh-water shells. Proceedings of the U. S. National Museum, 8: 255-289.","Dayrat B (2005) Towards integrative taxonomy. Biological Journal of the Linnean Society, 85: 407-415.","Dayrat B (2009) Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa, 2068(1): 1-26.","Dayrat B (2010) Comparative anatomy and taxonomy of Onchidium vaigiense (Gastropoda: Pulmonata: Onchidiidae). Molluscan Research, 30: 87-101.","Dayrat B, Conrad M, Balayan S, White TR, Albrecht C, Golding R, Gomes SR, Harasewych MG & de Frias Martins AM (2011) Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): New insights from increased taxon sampling. Molecular Phylogenetics and Evolution, 59(2): 425-437.","Dayrat B & Goulding TC (2017) Systematics of the onchidiid slug Onchidina australis (Mollusca: Gastropoda: Pulmonata). Archiv fur Molluskenkunde, 146: 121-133.","Dayrat B, Goulding TC, Apte D, Bhave V & Xuan QN (2017) A new genus and four new species of onchidiid slugs from Southeast Asia (Mollusca: Gastropoda: Pulmonata: Onchidiidae). Journal of Natural History, 51(31-32): 1851-1897.","Dayrat B, Goulding TC, Apte D, Bhave V, Comendador J, Quang NX, Tan SK & Tan SH (2016) Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca: Gastropoda: Pulmonata: Onchidiidae). ZooKeys, 636: 1-40.","Fleming J (1822) The Philosophy of Zoology. Archibald Constable & Co., Edinburgh, 2 vols [vol. 1: 432 pp.; vol. 2: 618 pp.].","Folmer O, Black M, Hoeh W, Lutz R & Vrijenhoek R (1994) DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology, 3(5): 294-299.","Goulding TC, Khalil M, Tan SH & Dayrat B (2018a) A new genus and a new species of onchidiid slugs from eastern Indonesia (Gastropoda: Euthyneura: Onchidiidae). Raffles Bulletin of Zoology, 66: 337-349.","Goulding TC, Khalil M, Tan SH & Dayrat B (2018b) Integrative taxonomy of a new and highly-diverse genus of onchidiid slugs from the Coral Triangle (Gastropoda: Pulmonata: Onchidiidae). ZooKeys, 763: 1-111.","Goulding TC, Tan SH, Tan SK, Apte D, Bhave V, Narayana S, Salunkhe R & Dayrat B (2018c) A revision of Peronina Plate, 1893 (Gastropoda: Euthyneura: Onchidiidae) based on mitochondrial and nuclear DNA sequences, morphology, and natural history. Invertebrate Systematics, 32: 803-826.","Gray JE (1850) Figures of molluscous animals selected from various authors. Etched for the use of students by M. E. Gray. Volume 4. Longman, Brown, Green and Longmans, London, iv + 219 pp.","Guindon S & Gascuel O (2003) A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Systematic Biology, 52: 696-704.","Hassouna N, Mithot B & Bachellerie JP (1984) The complete nucleotide sequence of mouse 28S rRNA gene. Implications for the process of size increase of the large subunit rRNA in higher eukaryotes. Nucleic Acids Research, 12: 3563-3583.","Hoffmann H (1928) Zur Kenntnis der Oncidiiden. Zoologische Jahrbucher, 55: 29-118.","ICZN (1999) International Code of Zoological Nomenclature.Fourth Edition. The International Trust for Zoological Nomenclature, London, UK, 306 pp.","Johnson RI (1969) Semper's Reisen im Archipel der Philippenen, wissenshaftliche Resultate, 1867-1916. A complete collation. Journal of the Society for the Bibliography of Natural History, 5: 144-147.","Kumar S, Stecher G & Tamura K (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular Biology and Evolution, 33(7): 1870-1874.","Labbe A (1934a) Les Silicodermes (Labbe) du Museum d'Histoire naturelle de Paris. Premiere partie : Classification, formes nouvelles ou peu connues. Annales de l'Institut Oceanographique, 14: 173-246.","Labbe A (1934b) Opisthobranches et Silicodermes (Oncidiades). Resultats scientifiques du Voyage aux Indes Orientales Neerlandaises, 2(14): 3-83, pl. I.","Lesson RP (1830-1831). Voyage autour du monde, Execute par Ordre du Roi, sur La Corvette de Sa Majeste, La Coquille, pendant les annees 1822, 1823, 1824 et 1825, sous le ministere et conformement aux Instructions de S.E.M. le Marquis de Clermont-Tonnerre, Ministre de la Marine; Et publie sous les auspices de son Excellence Mgr le Cte de Chabrol, Ministre de la Marine et des Colonies, par M.L.I. Duperrey, Capitaine de Fregate, Chevalier de Saint-Louis et Membre de la Legion d'Honneur, Commandant de l'Expedition. Zoologie, par M. Lesson. Tome Second. 1re Partie. Arthus Bertrand, Libraire- Editeur, Paris, pp. 1-471, pls. 1-16 [pp. 241-471 published on November 15, 1831; plates on molluscs published between January 9, 1830 and December 22, 1831; plate 14 published on November 15, 1831; see Cretella, 2010].","Milne I, Wright F, Rowe G, Marshal DF, Husmeier D & McGuire G (2004) TOPALi: Software for Automatic Identification of Recombinant Sequences within DNA Multiple Alignments. Bioinformatics, 20: 1806-1807.","Morch OAL (1872) Catalogue des mollusques terrestres et fluviatiles des anciennes colonies du Bengale. Journal de Conchyliologie, 20: 303-345.","Palumbi S (1996) Nucleic acid II: The polymerase chain reaction. In: Hillis D, Moritz C & Mable B (eds.) Molecular Systematics. Second Edition. Sunderland, Massachusetts: Sinauer Press. Pp. 205-247.","Plate LH (1893) Studien uber opisthopneumone Lungenschnecken, II, Die Oncidiidien. Zoologische Jahrbucher, 7: 93-234.","Quoy JRC & Gaimard JP (1824-1826) Zoologie. Voyage autour du Monde entrepris par ordre du Roi, sous le ministere et conformement aux instructions de S. Exc. M. Le Vicomte du Bouchage, secretaire d'Etat au Departement de la Marine, execute sur les corvettes de S. M. l'Uranie et la Physicienne, pendant les annees 1817, 1818, 1819 et 1820; publie par M. Louis de Freycinet. Pillet Aine, Paris, 672 pp. [pp. 425-496 published in 1825; for detailed collation, see Sherborn & Woodward, 1901].","Quoy JRC & Gaimard JP (1832-1833) Zoologie. Tome Second. Voyage de decouvertes de l'Astrolabe execute par ordre du Roi, pendant les annees 1826-1827-1828-1829, sous le commandement de M. J. Dumont d'Urville. J. Tastu, Paris, 686 pp. [pp. 1-320 published in 1832 and pp. 321-686 published in 1833; for collations, see Sherborn & Woodward, 1901].","Rafinesque CS (1815) Analyse de la Nature ou tableau de l'univers et des corps organises. [For the author], Palermo, 223 pp.","Ronquist F & Huelsenbeck JP (2003) MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics, 19(12): 1572-1574.","Semper C (1880-1885) Dritte Familie, Onchididae [for Onchidiidae]. In: Semper C (ed.) Reisen im Archipel der Philippinen, Zweiter Theil. Wissenschaftliche Resultate. Dritter Band. Landmollusken. CW Kreidel's Verlag, Wiesbaden, pp.251-290, pls. 19-27 [pp. 251-264 and pls. 19-20, 22-23 published in 1880, pp. 265-290 and pl. 21 published in 1882, pls. 24-27 published in 1885; for detailed collations, see Johnson, 1969].","Sherborn CD & Woodward BB (1901) Notes on the dates of publication of the natural history portions of some French voyages. - Part I. 'Amerique meridionale'; 'Indes orientales'; 'Pole Sud' ('Astrolabe' and 'Zelee); 'La Bonite'; 'La Coquille'; and L'Uranie et Physicienne'. Annals and Magazine of Natural History, 7(40): 388-392.","Stoliczka F (1869) The Malacology of lower Bengal and the adjoining provinces. Journal of the Asiatic Society of Bengal, 38: 86-111.","Tapparone-Canefri C (1883) Fauna malacologica delle Nuova Guinea e delle Isole adiacenti. Annali del Museo Civico di Storia Naturale, Genova, 19: 1-313.","Vonnemann V, Schrodl M, Klussmann-Kolb A & Wagele H (2005) Reconstruction of the phylogeny of the Opisthobranchia (Mollusca: Gastropoda) by means of 18S and 28S rRNA gene sequences. Journal of Molluscan Studies, 71: 113-125.","Wade CM & Mordan PB (2000) Evolution within the gastropod molluscs; using the ribosomal RNA gene-cluster as an indicator of phylogenetic relationships. Journal of Molluscan Studies, 66: 565-570.","Westerlund CA (1883) Noch einige von der Vega-Expedition gesammelte Mollusken. Nachrichtsblatt der deutschen malakozoologischen Gesellschaft, 15: 164-166."]}

Goulding, Tricia C., Khalil, Munawar, Tan, Shau Hwai, Dayrat, Benoît (2018): A new genus and a new species of onchidiid slugs from eastern Indonesia (Gastropoda: Euthyneura: Onchidiidae). Raffles Bulletin of Zoology 66: 337-349, DOI: http://doi.org/10.5281/zenodo.5358903, {"references":["Audouin V & Milne-Edwards H (1832-1834) Recherches pour server a l'histoire naturelle du littoral de la France. Crochard, Paris, 2 vols [vol. 1, 406 pp.; vol. 2, 290 pp., 8 pls].","Baker HB (1938) Nomenclature of Onchidiidae. The Nautilus, 51: 85-88.","Buchannan F (1800) An account of the Onchidium, a new genus of the class of vermes, found in Bengal. Transactions of the Linnean Society of London, 5: 132-134, pl. 5.","Dall WH (1885) Notes on some Floridian land and fresh-water shells. Proceedings of the U. S. National Museum, 8: 255-289.","Dayrat B (2009) Review of the current knowledge of the systematics of Onchidiidae (Mollusca: Gastropoda: Pulmonata) with a checklist of nominal species. Zootaxa, 2068(1): 1-26.","Dayrat B, Conrad M, Balayan S, White TR, Albrecht C, Goulding R, Gomes SR, Harasewych MG & de Frias Martins AM (2011) Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): New insights from increased taxon sampling. Molecular Phylogenetics and Evolution, 59(2): 425-437.","Dayrat B, Goulding TC, Apte D, Bhave V, Comendador J, Quang NX, Tan SK & Tan SH (2016) Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca: Gastropoda: Pulmonata: Onchidiidae). ZooKeys, 636: 1-40.","Dayrat B & Goulding TC (2017) Systematics of the onchidiid slug Onchidina australis (Mollusca: Gastropoda: Pulmonata). Archiv fur Molluskenkunde, 146: 121-133.","Dayrat B, Goulding TC, Apte D, Bhave V & Xuan QN (2017) A new genus and four new species of onchidiid slugs from Southeast Asia (Mollusca: Gastropoda: Pulmonata: Onchidiidae). Journal of Natural History, 51(31-32): 1851-1897.","Fleming J (1822-1824) Peronia. In: [no named editor] Encyclopedia Britannica, Vol. 5. Supplement to the 4-6th Edition. Edinburgh. P. 574.","Folmer O, Black M, Hoeh W, Lutz R & Vrijenhoek R (1994) DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology, 3(5): 294-299.","Fretter V (1943) Studies in the functional morphology and embryology of Onchidella celtica (Forbes and Hanley) and their bearing on its relationships. Journal of the Marine Biological Association of the United Kingdom, 25: 685-720.","Goulding TC, Tan SH, Tan SK, Apte D, Bhave V, Narayana S, Salunkhe R & Dayrat B (in press-b) A revision of Peronina Plate, 1893 (Gastropoda: Euthyneura: Onchidiidae) based on mitochondrial and nuclear DNA sequences, morphology, and natural history. Invertebrate Systematics.","Guindon S & Gascuel O (2003) A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Systematic Biology, 52: 696-704.","Kumar S, Stecher G & Tamura K (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular Biology and Evolution, 33(7): 1870-1874.","Labbe A (1934) Les Silicodermes (Labbe) du Museum d'histoire naturelle de Paris. Premiere partie: Classification, formes nouvelles ou peu connues.Annales de l'Institut Oceanographique de Monaco, 14: 173-246.","Milne I, Wright F, Rowe G, Marshal DF, Husmeier D & McGuire G (2004) TOPALi: Software for automatic identification of recombinant sequences within DNA multiple alignments. Bioinformatics, 20: 1806-1807.","Palumbi S (1996) Nucleic Acid II: The Polymerase Chain Reaction. In: Hillis D, Moritz C & Mable B (eds.) Molecular Systematics. Second Edition. Sunderland, Massachusetts: Sinauer Press. Pp. 205-247.","Plate L von (1893) Studien uber opisthopneumone Lungenschnecken, II, Die Onciidien. Zoologische Jahrbucher, Anatomie, 7: 93-234, pl. 7-12.","Rafinesque CS (1815) Analyse de la nature ou tableau de l'univers et des corps organises. [self-published by the author], Palerme, 223 pp.","Reid DG, Dyal P & Williams ST (2010) Global diversification of mangrove fauna: a molecular phylogeny of Littoraria (Gastropoda: Littorinidae). Molecular Phylogenetics and Evolution, 55(1): 185-201.","Ronquist F & Huelsenbeck JP (2003) MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics, 19(12): 1572-1574.","Semper C (1880-1885) Dritte Familie, Onchidiidae. In: Semper C (ed.) Reisen im Archipel der Philippinen, Wissenschaftliche Resultate, III (7); Wiesbaden: C. W. Kreidel. Pp. 251-264 [1880], 265-290 [1882], pls. 19-20, 22-23 [1880], pl. 21 [1882], pls. 24-27 [1885].","Stantschinsky W (1907) Zur Anatomie und Systematik der Gattung Oncidium. Zoologische Jahrbucher, Systematik, Geographie und Biologie der Tiere, 25: 353-402.","Stoliczka F (1869) The malacology of Lower Bengal. Journal of the Asiatic Society of Bengal, 38: 86-111, pls 14-15.","Stringer BL (1963) Embryology of the New Zealand Onchidiidae and its bearing on the classification of the group. Nature, 197: 621-622.","Van Wyhe J & Drawhorn GM (2015) \"I am Ali Wallace\": The Malay assistant of Alfred Russel Wallace. Journal of the Malaysian Branch of the Royal Asiatic Society, 88(1): 3-31.","Wade CM & Mordan PB (2000) Evolution within the gastropod molluscs; using the ribosomal RNA gene-cluster as an indicator of phylogenetic relationships. Journal of Molluscan Studies, 66: 565-570.","Westerlund CA (1883) Noch einige von der Vega-Expedition gesammelte Mollusken. Nachrichtsblatt der deutschen malakozoologischen Gesellschaft, 15: 164-166.","White TR, Conrad MM, Tseng R, Balayan S, Golding R, de Frias Martins AM & Dayrat BA (2011) Ten new complete mitochondrial genomes of pulmonates (Mollusca: Gastropoda) and their impact on phylogenetic relationships. BMC Evolutionary Biology, 11: 295."]}