taxonID	type	description	language	source
411A87B3FF919F1FFF7AC590FC98FCE3.taxon	materials_examined	Type species. Chiton laevis Montagu, 1803, non Pennant, 1777 (= Chiton septemvalvis Montagu, 1803), SD Gray 1847. Genus distribution and range. NE Atlantic Ocean, Indian Ocean, West Pacific Ocean from Japan to Australia and New Zealand, SE Pacific, Antarctica. Miocene-Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC48CFD85F9CF.taxon	description	(Fig. 2 A)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC48CFD85F9CF.taxon	materials_examined	Type material. Holotype (USNM 24212). Type locality. Japan, Bonin Islands. Material examined. South China Sea, Hainan Island, stn. 15, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, intertidal, on old corals, 1 spm, BL 5.0 mm, 19.11.2016, leg. J. Zhang; stn. 27, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 2 - 5 m, on stones covered with red crustose algae, 1 spm, BL 5.5 mm, 24.11.2016, leg. B. Sirenko.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC48CFD85F9CF.taxon	distribution	Distribution. South China Sea, Vietnam from Con Dao Archipelago to Beibu Gulf (Gulf of Tongkin), China, Hainan Island and Japan, Bonin Islands.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC48CFD85F9CF.taxon	discussion	Remarks. The specimens from Hainan Island have the tegmentum and girdle of yellow or dark red color with wide white and narrow black girdle bands at both sides next to the sutures of valves I / II and VII / VIII and sometimes II / III and VI / VII as well.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC190FA86F863.taxon	materials_examined	Type species. Lectotype (ITZ), designated by Kaas & Van Belle 1985. Type locality. Indonesia, Sanana Bay, E coast of Sulawesi, on reef.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC190FA86F863.taxon	distribution	Distribution. Indonesia and Hong Kong.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF919F1FFF7AC190FA86F863.taxon	discussion	Remarks. In the studied area the only specimen was found in Hong Kong (Bullock & Harper 1994).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF969F19FF7AC0A7FBB9FF44.taxon	materials_examined	Type species. Chiton textilis Gray, 1828, SD Gray 1847. Genus distribution and range. Widely distributed genus, especially abundant in tropical and subtropical waters, only few species inhabit boreal and antiboreal waters. Miocene-Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F19FF7AC611FCFFFB44.taxon	description	(Fig. 2 B)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F19FF7AC611FCFFFB44.taxon	description	Ischnochiton (Simplichnochiton) boninensis; Dell’Angelo et al. 1990: 36.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F19FF7AC611FCFFFB44.taxon	materials_examined	Type material. UUZM. Type locality. Japan, Bonin Islands. Material examined. South China Sea, Hainan Island, stn. 2, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, SCUBA, depth 1 – 3 m, on stones, 11 spms, BL – 5.0 – 11.0 mm, 13.11.2016, leg. B. Sirenko, S. Grebelniy; stn. 27, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 2 – 5 m, on stones covered with red crustose algae, 1 spm, BL – 15.0 mm, 24.11.2016, leg. B. Sirenko; stn. 27, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 1.5 – 2 m, on stones, 21 spms, BL – 6.0 – 12.0 mm, 24.11.2016, leg. B. Sirenko.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F19FF7AC611FCFFFB44.taxon	distribution	Distribution. South China Sea, north Vietnam from 18 ° 06 ’ 05 ’’ N, 106 ° 27 ′ 55 ’’ E to Cat Ba Island (20 ° 47 ’ 23 ’’ N, 107 ° 06 ’ 13 ’’ E), China, Hainan Island, Hong Kong, Yellow Sea, Qingdao, near south Korea and south Japan, from intertidal to depth 2 – 5 m.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F19FF7AC611FCFFFB44.taxon	discussion	Remarks. Ischnochiton boninensis often inhabits the same regions as I. comptus along the coast of North Vietnam and south China. They are very similar but easy to differentiate by their dorsal scales. The scales of I. boninensis have ribs while the scales of I. comptus are smooth and glossy. In order to see ribs under a light microscope it is necessary to dry the girdle slightly with paper.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F1AFF7AC22AFD4EFD89.taxon	description	(Fig. 2 C)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F1AFF7AC22AFD4EFD89.taxon	description	1995: 105; 1998: 150; 2000: 13, pl. 6, fig. 14; 2001: 196, fig. 2; 2006: 212; 2017: 49, 732, pl. 5, fig. 1; Hasegawa et al. 2001: 3; Xu 2008: 457; Zhang et al. 2015: 98, fig. 5; Zhang et al. 2016: 11, fig. 9; Owada 2016: 260, figs 4 F – J, 5 E – H; 2018: 284, Table 3.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F1AFF7AC22AFD4EFD89.taxon	materials_examined	Type material. USNM 1562, holotype by monotypy. Type locality. Japan, Izu-Oshima Island, south of Sagami Bay. Material examined. South China Sea, Hainan Island, Sanya, 3 spms, BL 14.0 – 20.0 mm, 21.03.1958; Sanya, on rocks, intertidal, 1 spm, BL 13.0 mm, 21.03.1958; Sanya, Luhuitou reef, intertidal, 1 spm, BL 16.0 mm, 30.12.1959; stn. 7, 19 ° 24 ’ 22 ’’ N, 110 ° 44 ′ 03 ’’ E, intertidal, on stones, 11 spms, BL 5.0 – 12.0 mm, 15.11.2016, leg. B. Sirenko and S. Grebelniy; stn. 27, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 2 – 5 m, on stones covered with red crustose algae, 1 spm, BL 8.5 mm, 24.11.2016, leg. B. Sirenko; stn. 29, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 1.5 – 2.0 m, on stones, 21 spms, BL 6.5 – 12.0 mm, 24.11.2016, leg. B. Sirenko.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F1AFF7AC22AFD4EFD89.taxon	distribution	Distribution. South China Sea, Beibu Gulf (Gulf of Tongkin) from 17 ° 56 ’ N to 20 ° 47 ’ N, Hainan Island, Hong Kong, Taiwan, Qingdao, south Korea, Japan from Okinawa Island to Hakodate Bay, Philippines, and possibly Indonesia (Nierstrasz 1905) and even Australia (Leloup 1941) from intertidal to 6 m depth.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF979F1AFF7AC22AFD4EFD89.taxon	discussion	Remarks. Owada (2016) described the new cryptic species Ischnochiton manazuruensis Owada, 2016, which is very similar to I. comptus. These species are frequently misidentified. The main morphological difference in these species is the structure of tegmentum of the central areas. The central areas of I. comptus are covered with conspicuous quincuncial granules whereas the same areas are smooth or very weakly granulated in I. manazuruensis. Molecular analyses revealed that I. comptus and I. manazuruensis are separated by a relatively big genetic gap, similar to the gap between either of these species and I. boninensis. Ischnochiton comptus has a rather wide distribution, which extends from north Japan and Korea to North Vietnam, whereas I. manazuruensis is only known in the area between Sagami Bay and Kyushu.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF949F1AFF7AC450FE19FAF1.taxon	materials_examined	Type material. Lectotype (USNM 24117), designated by Ferreira 0 1.03. 1983 in MS, published by Kaas & Van Belle (1987). Type locality. Hong Kong.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF949F1AFF7AC450FE19FAF1.taxon	distribution	Distribution. Korea, China, Qingdao, Hong Kong, and Vietnam.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF949F1AFF7AC450FE19FAF1.taxon	discussion	Remarks. Bullock & Harper (1994) demonstrated the differences between L. bisculpta and L. coreanica (Reeve, 1847), which are very similar to each other. We also found that L. bisculpta differs from the latter by the absence of radial ribs on the head valve and by having 6 – 8 longitudinal grooves in the dorsal scales (vs. 16 – 19 grooves in L. coreanica).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF949F1AFF7AC282FD1FF8D6.taxon	materials_examined	Type material. Holotype (BMNH 198244). Type locality. Hong Kong, outside Tolo Channel. Distribution. South China Sea from Hong Kong (22 ° 22 ′ N) south to Hon Cau Island, Vietnam (11 ° 13 ′ N), 7 – 12 m. Remarks. This is a rather rare species. At present, we know three specimens only, the holotype from Hong Kong and two from Vietnam (Sirenko 2016 a, c).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF949F1AFF7AC55AFDFDFC82.taxon	materials_examined	Type species. Chiton mertensii Middendorff, 1847, by monotypy. Genus distribution and range. The northern Pacific and northern Indian Oceans and also in Peruvian and north Chilean waters. Miocene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F1BFF7AC3D6FAE8FA38.taxon	materials_examined	Type species. Chiton janeirensis, non Gray, 1828; fide Thiele 1893 = Chiton affinis Issel, 1869, SD Thiele (1909). Genus distribution and range. Widely distributed in tropical and subtropical waters. Eocene-Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F1BFF7AC7A1FC7AFD79.taxon	description	(Fig. 2 D)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F1BFF7AC7A1FC7AFD79.taxon	materials_examined	Type material. Lectotype (BMNH 1986. 136 / 1), designated by Kaas & Van Belle 1987. Type locality. Korean Archipelago. Material examined. South China Sea, Hainan Island, stn. 2, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, depth 1 – 3 m, on stones, 5 spms, BL 11.0 – 24.0 mm, 13.11.2016, leg. B. Sirenko, S. Grebelniy. Distribution. Japan, Korea, Qingdao, Hong Kong, Hainan, Beibu Gulf (Gulf of Tongkin) (Cat Ba Island). Remarks. This is the first record of L. coreanica from Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F1BFF7AC40AFA34FB1C.taxon	materials_examined	Type material. Holotype (MNHN-IM- 2000 - 6137). Type locality. Vietnam, Cap St. Jacques, Vung Tau. Distribution. South China Sea from Hong Kong to South Vietnam (Vung Tau). Remarks. This species differs from the above mentioned species of the genus Lepidozona by having prominent radial ribs on the head valve, lateral areas of intermediate valves and postmucronal area of the tail valve.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F14FF7AC2CBFBFFFE64.taxon	description	(Fig. 2 E)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F14FF7AC2CBFBFFFE64.taxon	description	13. Chiton (Rhyssoplax) komaianus; Kaas & Van Belle 1980: 70; 1998: 104; Kaas et al. 2006: 200 – 203, fig. 79, map 36 (bibliography and synonymy).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F14FF7AC2CBFBFFFE64.taxon	materials_examined	Type material. Kaas et al. (2006) reported that the type is in ZICS, but we did not find this institute or type. Type locality. Japan, Prov. Kii (Wakayama Prefecture), Seto. Material examined. South China Sea, Hainan Island. 57 - 1051, 1 spm, BL 12 mm; stn. 4, 19 ° 38 ’ 12 ’’ N, 111 ° 01 ’ 52 ’’ E, intertidal pool, on rocks, 6 spms, BL 3.0 – 6.0 mm, 14.11.2016, leg. B. Sirenko; stn. 6, 19 ° 38 ’ 12 ’’ N, 111 ° 01 ′ 52 ’’ E, depth 2 – 3 m, on stones, 1 spm, BL 16.0 mm, 14.11.2016, leg. B. Sirenko; stn. 10, 18 ° 23 ’ 17 ’’ N, 109 ° 21 ’ 59 ’’ E, SCUBA, depth 2 – 3 m, on stones, 1 spm, BL 5.0 mm, 17.11.2016, leg. B. Sirenko; stn. 13, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ’ 40 ’’ E, depth 1 – 3 m, on stones and old corals, 2 spms, BL 3.0 – 10.0 mm, 15.11.2016, leg. B. Sirenko; stn. 16, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, depth 2 – 3 m, in sand, 3 intermediate valves, 19.11.2016, leg. B. Sirenko; stn. 17, 18 ° 16 ’ 30 ’’ N, 109 ° 43 ’ 26 ’’ E, SCUBA depth 3 – 4 m, on stones, 1 spm, BL 3.0 mm, 20.11.2016, leg. B. Sirenko; stn. 26, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ’ 40 ’’ E, intertidal – 1.5 m, on stones, 4 spms, BL 5.0 – 28.0 mm, 15.11.2016, leg. B. Sirenko, S. Grebelniy.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F14FF7AC2CBFBFFFE64.taxon	distribution	Distribution. Hong Kong, Hainan Island and South Vietnam, South Japan. Bullock (1988) states that it lives in Malaya, Philippines and possibly south of the Admiralty Islands as well.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF959F14FF7AC2CBFBFFFE64.taxon	discussion	Remarks. Rhyssoplax komaiana is one of the abundant chitons of Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC285FAE7F80B.taxon	materials_examined	Type material. Holotype (ZMHU). Type locality. Japan, off Tago, 75 m.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC285FAE7F80B.taxon	distribution	Distribution. Japan, Hong Kong (Van Belle 1982) and Xisha Islands (Huang & Xu 1964).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC285FAE7F80B.taxon	discussion	Remarks. This rare chiton was found sporadically in the studied area in Hong Kong and Xisha Islands.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC571FCC2FBF7.taxon	description	(Fig. 2 F)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC571FCC2FBF7.taxon	materials_examined	Type material. Holotype (AM). Type locality. Queensland, Keppel Bay, Emu Park. Material examined. South China Sea. Guangxi Province of China, MBM 100143, 18 – 23 m, 2 spms, BL 9.0 – 11.5 mm, 26.05.1978.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC571FCC2FBF7.taxon	distribution	Distribution. Northeastern Queensland, Vietnam (from Cau to Cat Ba islands) and Guangxi Province of South China.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9A9F14FF7AC571FCC2FBF7.taxon	discussion	Remarks. The species is rather abundant in Vietnamese part of the Beibu Gulf (Gulf of Tongkin). In the Guangxi Province the species was documented for the first time.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9B9F10FF7AC7A1FF45FD7E.taxon	description	(Figs 3 A, B, 5 – 12)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9B9F10FF7AC7A1FF45FD7E.taxon	description	synonymy); Sirenko 2012: 80, pls. 13 F; 16 A; Saito 2017: 735, pl. 7, fig. 9.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9B9F10FF7AC7A1FF45FD7E.taxon	materials_examined	Type material. Lectotype (MNHN 6058) designated by Strack (1986). Type locality. Tonga, Tongatapu (21 ° 10 ’ S, 175 ° 13 ’ W). Material examined. Lectotype (MNHN 6058); South China Sea, Hainan Island. MBM 100297, 55 - 610, 1 spm, forma typical, BL 12 mm, 8 spms, forma costata, BL 6.0 – 19.0 mm, 20.04.1955; 55 - 640, 3 spms, forma typica, BL 14.0 – 15.0 mm, 14 spms, forma costata, BL 8.0 – 22.0 mm, 23.04.1955; Xincun, depth 0.5 m, on old corals 6 spms, forma costata, BL 9.0 – 15.0 mm, 21.04.1958, leg. O. Scarlato; Xincun, depth 1.0 m, on old corals, 2 spms, forma costata, BL 9.0 – 10.0 mm, 21.04.1958, leg. O. Scarlato; Xisha Islands, 58 M- 1246, 4 spms, forma typica, BL 25.0 – 29.0 mm; 1 spm, forma typica, BL 34.0 mm, 23.05.1981; MBM 100328, 4 spms, forma typica, BL 16.0 – 28.0 mm, 1 spm, forma costata, BL 29.0 mm; Guangdong Province, 2 spms, forma costata, 10.0 – 15.0 mm; Submersed reef, R / V Akademik Shirshov, 18 ° 39 ’ N, 111 ° 40 ’ E, depth 0.5 – 2.0 m, on old corals, 1 spm, forma typical, BL 15.0 mm, 25.07.1981,	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9B9F10FF7AC7A1FF45FD7E.taxon	distribution	Distribution. The species has a wide distribution in the Indo-Pacific: Andaman Sea, Vietnam, South China including Guangdong Province, Hainan Island and Xisha Islands, Australia and Samoa as well.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF9B9F10FF7AC7A1FF45FD7E.taxon	discussion	Remarks. While examining L. lamellosa, we found two forms: L. lamellosa forma typica (Figs 3 A, 5 – 6) and the new form L. lamellosa forma costata (Figs 3 B, 7 – 12). Both forms differ from each other in the sculpture of tegmentum of the pleural areas. Lucilina lamellosa forma typica has demonstrated the similarity of it with the lectotype (MNHN 6058) from Tonga. Both forms of L. lamellosa have a distinct diagonal ridge sculptured with concentric shingle-like ledges. In L. lamellosa forma typica, pleural areas are also sculptured with shingle-like ledges (Fig. 5 D), whereas in L. lamellosa forma costata, the pleural areas are sculptured with longitudinal ribs (Fig. 7 E). The latter form is similar to Lucilina nigropunctata (Carpenter, 1865) in its sculpture of pleural areas. L. lamellosa forma costata differs from L. nigropunctata in having subtriangular pits on the central area and in the absence of radiating rows of small tubercles in lateral areas. Moreover, forma costata has the tail valve wider than the head valve and the longitudinal ribs do not curve towards the jugum as in L. nigropunctata. Lucilina lamellosa forma costata is also similar to L. truncata (Sowerby, 1841) from the Philippines but differs from the latter in having longitudinal ribs on the pleural areas (vs. more or less concentrical, distinctly spaced, wavy grooves in L. truncata), subtriangular pits on the central area (pits are unknown in L. truncata). Both forms of L. lamellosa were found near Fujian Province, Hainan Island and Xisha Islands. The forma costata inhabits the coast of Guangdong Province. The examined specimen of L. lamellosa forma typica (BL 15.0 mm) has a radula of 4.2 mm in length and 27 gills extended from valve II to valve VIII. The slit formula of this specimen is 9 / 1 / 13. The radula of the specimen of L. lamellosa forma costata (BL 14.0 mm) is 4.5 mm long and its slit formula is 9 / 1 / 15. A smaller specimen of L. lamellosa forma costata (BL 9.0 mm) has a radula 3.5 mm long with 34 transverse rows of mature teeth and 20 gills extended from valve III to valve VII. The slit formula of this specimen is 9 / 1 / 14. The latter specimen is similar to L. mariae Kaas et al., 2006 in having longitudinal ribs on the pleural areas of the intermediate valves, but differs from it in having sparsely scattered subtriangular pits on the central area (vs. no pits in L. mariae). Because both forms differ from each other only in the sculpture of the tegmentum of the pleural area and because there are specimens with intermediate sculpture, we refrain from describing a new subspecies or a new species. We assign a registration number of the Zoological Institute RAS (ZISP 2301) to Lucilina lamellosa forma costata.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC7A1FD58FE2E.taxon	materials_examined	Type material. Holotype (BMNH). Type locality. Hong Kong, Tolo Channel (Channel Rocks), 10 m. Distribution. Only known from the type locality.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC524FC44FC21.taxon	description	(Fig. 3 C)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC524FC44FC21.taxon	materials_examined	Type material. The holotype (ZISP 2 243). Type locality. Vietnam, Gulf of Tongkin, Cat Ba Islands, 20 ° 47.090 ′ N, 107 ° 06.103 ′ E, 1 – 1.5 m, SCUBA, on old shells. Material examined. South China Sea, Hainan Island, stn. 13, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, depth 2 – 3 m, on old corals, 1 spm, BL 9.0 mm, 19.11.2016, leg. B. Sirenko.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC524FC44FC21.taxon	distribution	Distribution. South China Sea, Beibu Gulf (Gulf of Tongkin) and Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC524FC44FC21.taxon	discussion	Remarks. This is the first record of L. tenuicostata from Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC332FDC0F9DA.taxon	description	(Figs 13 – 15)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC332FDC0F9DA.taxon	materials_examined	Type material. Holotype NMV P 18471. Type locality. Queensland, Capricorn Group, Heron Island. Material examined. South China Sea, Hainan Island, stn. 5, 19 ° 38 ’ 12 ’’ N, 111 ° 01 ′ 52 ’’ E, intertidal, on stones, 2 spms, BL 4.0 – 6.0 mm, 14.11.2016, leg. B. Sirenko; stn. 15, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, intertidal, on old corals, 1 spm, BL 3.0 mm, 19.11.2016, leg. B. Sirenko; stn. 27, 18 ° 18 ′ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 2 – 5 m, on stones covered with red crustose algae, 1 spm, BL 9.5 mm, 24.11.2016, leg. B. Sirenko.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC332FDC0F9DA.taxon	distribution	Distribution. The species is known from Maldives Islands, South Vietnam, Hainan Island and Australia.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC332FDC0F9DA.taxon	discussion	Remarks. The studied specimen (BL 5.0 mm) has a radula 1.5 mm long with 35 transverse rows of mature teeth and 20 gills extending from valve III to valve VII. The slit formula of this specimen is 8 / 1 / 10. This is the first record of L. tilbrooki from Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF839F0DFF7AC1A8FB8FF8FB.taxon	materials_examined	Type species. Chiton undulatus Quoy & Gaimard, 1835, non Wood, 1828 (= Onithochiton neglectus de Rochebrune, 1881) SD Gray 1847. Genus distribution and range. The genus is known from South Africa, the Indian Ocean, Australia, New Zealand, Vietnam, China, Japan and the Central Pacific Ocean. Miocene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF809F08FF7AC1E7FF72FD89.taxon	description	(Fig. 3 D)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF809F08FF7AC1E7FF72FD89.taxon	materials_examined	Type material. Two syntypes (ANS 80571). Type locality. Japan, Hizen, Hirado. Material examined. South China Sea, Guangdong Province. MBM 100243, 45 - 378, 6 spms, BL 20.0 – 30.0 mm, 0 5.04.1954.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF809F08FF7AC1E7FF72FD89.taxon	distribution	Distribution. Japan, Korea, Taiwan, Guangdong Province and Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF809F08FF7AC1E7FF72FD89.taxon	discussion	Remarks. Most specimens from Guangdong Province studied by us have features which are slightly similar to that of O. stracki Sirenko, 2012, namely they have spicules on the girdle, the girdle is not leathery and the sculpture of the tegmentum is stronger. Hiroshi Saito (personal communication) found that the specimens from central Japan have a smooth, glossy tegmentum and a leathery girdle whereas those from south Japan have a rather strong sculpture. He supposed also that the morphology of the sculpture and spicules change gradually from north to south.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC1EFFC5BF834.taxon	materials_examined	Type species. Chiton spinosus Bruguiere, 1792, SD Gray 1847. Genus distribution and range. The genus Acanthopleura has been recorded from four well separated areas: the western part of the Indian Ocean, the East Indies to the central part of the Pacific Ocean, the western coast of South America, and the Caribbean area (Kaas et al. 2006). Miocene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC55AFC22FB94.taxon	materials_examined	Type material. Holotype (BMHN). Type locality. Hong Kong, Mirs Bay, intertidal.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC55AFC22FB94.taxon	distribution	Distribution. Only known from the holotype locality.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC55AFC22FB94.taxon	discussion	Remarks. Bullock & Harper (1994) considered Onithochiton sp. of Van Belle (1982) as Onithochiton hirasei which is “ quite variable in shell morphology and colour ”. Kaas et al. (2006) pointed out that O. margueritae differs from O. hirasei regarding the form of valves and the color of the girdle. Moreover, the dorsal girdle of O. margueritae has marginal spicules but without needle-like spicules.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC361FAD9F917.taxon	description	(Figs 3 E, 16 – 18)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC361FAD9F917.taxon	materials_examined	Type material. Holotype (ZISP 2175). Type locality. South China Sea, off South Vietnam, Nhatrang Bay, Nok Island. Material examined. South China Sea, China, Hainan Island. Xincun, sample 1, 1 spm, BL 17.0 mm, 19.04.1958, leg. O. Scarlato; stn 22, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ’ 40 ’’ E, depth 2 m, on old corals, 1 spm, BL 5.0 mm, 21.11.2016, leg B. Sirenko; stn 26, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ’ 40 ’’ E, intertidal – 1.5 m, on stones, 3 spms, BL 3.0 – 12.0 mm, 22.11.2016, leg. B. Sirenko, S. Grebelniy.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC361FAD9F917.taxon	distribution	Distribution. South China Sea, Vietnam from Phu Quy Island to Danang and Hainan.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF869F08FF7AC361FAD9F917.taxon	discussion	Remarks. The studied specimen (BL 11.0 mm) has a radula 3.4 mm long with 36 transverse rows of mature teeth and 11 gills extended from valve II to valve VII. The slit formula of this specimen is 8 / 1 / 0. Specimens of this species from Hainan Island differ from Onithochiton hirasei from Guangdong Province by having a coarser sculpture of the tegmentum and larger spicules of girdle. This is the first find of O. stracki from Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC7A1FE1BFAA2.taxon	description	(Fig. 3 F)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC7A1FE1BFAA2.taxon	materials_examined	Type material. Type material is presumably lost; neotype: CAS 0 44306, designated by Ferreira 1986. Type locality. Loo Choo Islands for the lost types and restricted to Buckner Bay, Okinawa, Japan for the neotype. Material examined. South China Sea, China, Hainan Island. Sanya, Luhuitou, on old corals, intertidal, 1 spm, BL 19.0 mm, 22.03.1958, leg. O. Scarlato; among live and dead corals, intertidal, 2 spms, BL 13 – 14 mm, 0 5.04.1958, leg. P. Ushakov; transect III, stn 1, sample 2, 8 spms, BL 16 – 26 mm, 19.03.1958, leg. A. Strelkov & P. Ushakov; stn 1, 2, intertidal, 2 spms, BL 21 – 32 mm, 20.03.1958, leg. A. Strelkov and P. Ushakov; Western beach, on rocks, 2 spms, BL 16 – 18 mm, 31.03.1958, leg. A. Gurjanova; Eastern Island stn 1, 1 spm, BL 32 mm, 0 6.04.1958, leg. A. Strelkov, P. Ushakov and Baoling Wu on rocks, 1 spm, BL 22.0 mm, 0 4.01.1960, leg. O. Scarlato; stn. 2, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, depth 1 – 3 m, on stones, 2 spms, BL 10.0 – 16.0 mm, 13.11.2016, leg. B. Sirenko; stn. 3, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, intertidal, on stones, 9 spms, BL 4.0 – 20.0 mm, 13.11.2016, leg. B. Sirenko; stn. 4, 19 ° 38 ’ 12 ’’ N, 111 ° 01 ′ 52 ’’ E, intertidal pool, on rocks, 4 spms, BL 28.0 – 32.0 mm, 14.11.2016, leg. B. Sirenko; stn. 11, 18 ° 23 ’ 17 ’’ N, 109 ° 51 ′ 29 ’’ E, intertidal, on rocks, 11 spms, BL 10.0 – 12.0 mm, 16.11.2016, leg. S. Grebelniy; stn. 12, 18 ° 23 ’ 17 ’’ N, 109 ° 51 ′ 29 ’’ E, intertidal, on rocks, 4 spms, BL 25.0 – 28.0 mm, 16.11.2016, leg. J. Zhang; stn. 26, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ′ 40 ’’ E, intertidal – 1.5 m, on stones, 3 spms, BL 30.0 – 32.0 mm, 22.11.2016, leg. B. Sirenko and S. Grebelniy; stn. 28, 18 ° 18 ’ 03 ’’ N, 109 ° 13 ′ 55 ’’ E, depth 1.5 – 2 m, on stones, 11 spms, BL 18.0 – 35.0 mm, 24.11.2016, leg. B. Sirenko; Xincun, Nanwanhou Id., stn 1, oyster bed, 2 spms, BL 23 – 24 mm, 19.04.1958, leg. O. Scarlato; North beach, transect I, stn 1, sample 1, 1 spm, BL 30 mm, 15.04.1958, leg. D. Naumov.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC7A1FE1BFAA2.taxon	distribution	Distribution. The species was reported from Shizuoka and Tanegashima Island, Japan, and southward to Taiwan, Hong Kong, Hainan and northern Vietnam up to Cat Ba Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC7A1FE1BFAA2.taxon	discussion	Remarks. Acanthopleura loochooana differs from Liolophura japonica which inhabits the same area by having incompletely reduced slits in the insertion plates of the tail valve (vs. smooth insertion plates without slits of tail valve in L. japonica).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC2B0FBE7F8EA.taxon	materials_examined	Type material. Unknown, types unascertained (Ferreira 1986). Type locality. Paulo Dama, Gulf of Siam.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC2B0FBE7F8EA.taxon	distribution	Distribution. Gulf of Siam (Leloup 1939), Hong Kong (Van Belle 1980) and Amami and Okinawa Islands (Saito & Yoshioka 1993).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF859F0BFF7AC2B0FBE7F8EA.taxon	discussion	Remarks. This species used to be considered as a forma of Liolophura japonica (Leloup 1939; Van Belle 1980). But Saito & Yoshioka (1993) regarded it as a distinct species (see remarks of L. japonica). Kaas et al. (2006) considered it also as a form of L. japonica. We follow here Saito & Yoshioka (1993).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC658FBD4FB1D.taxon	description	Dell'Angelo et al. 1990: 45; Ma 2004: 5, fig. 1, pl. 2, fig. F. Acanthopleura japonica; Ferreira 1986: 250, 272, figs 68 – 72, 1151 (bibliography and synonymy); Saito 1995: 108; 1998: 156; 2000: 19, pl. 9, fig. 10; 2001: 198; 2006: 215; 2017: 51, 734, pl. 7, fig. 7; Xu 2008: 457; Zhang et al. 2015: 101, fig. 7. Acanthopleura (Liolophura) japonica; Bullock & Harper 1994: 28, pls. 4 J – M, 6 D, E, 8 C, 9 A – B (bibliography). Liolophura (Liolophura) japonica; Kaas et al. 2006: 277, fig. 112, map 52 (bibliography and synonymy).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC658FBD4FB1D.taxon	materials_examined	Type material. Unascertained, maybe it is in Löbbecke Museum und Aquazoo, Düsseldorf (Schwabe in review). Type locality. Japan, Nagasaki.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC658FBD4FB1D.taxon	distribution	Distribution. Japan (from Hokkaido to Okinawa), the southern coast of Korea, Taiwan, Hong Kong and northern Vietnam (Cat Ba Island), intertidal zone.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC658FBD4FB1D.taxon	discussion	Remarks. Acanthopleura tenuispinosa (Leloup, 1939) described from the Gulf of Thailand is similar to L. japonica. According to Saito & Yoshioka (1993), L. japonica differs from A. tenuispinosa by having a mucro which is strongly projected posteriorly beyond the posterior margin (vs. raised and situated at slightly anterior to posterior margin in A. tenuispinosa). Moreover L. japonica, the callus of the tail valve is smooth or pectinated only in a lateral small portion (vs. pectinated except for middle portion in A. tenuispinosa), its dorsal spicules are large thick, cylindrical or flattened (vs. small, slender and cylindrical in A. tenuispinosa), the interior of the valves is dark brown to dark purplish brown (vs. light brown to greyish brown in A. tenuispinosa).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC7AEFA24FE8A.taxon	materials_examined	Type species. Chiton japonicus Lischke, 1873, OD. Genus distribution and range. Eastern and northeastern shores of Australia, and the western Pacific Ocean.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F04FF7AC282FE53F9CB.taxon	materials_examined	Type species. Chiton carmichaelis Gray, 1828 (= Chiton auratus Spalowsky, 1795), SD Gray (1847). Genus distribution and range. The genus is widespread in the South Atlantic as well as in the Indian and Pacific Oceans. Eocene – Recent	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F05FF7AC198FD25FE64.taxon	description	(Fig. 4 A)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F05FF7AC198FD25FE64.taxon	materials_examined	Type material. Holotype (ZISP 2177) and 10 paratypes (ZISP 2178). Type locality. South China Sea, off South Vietnam, Nhatrang Bay, Nok Island, 0 m. Material examined. South China Sea, Hainan Island, stn. 3, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, intertidal, on stones, 6 spms, BL 4.0 – 7.0 mm, 13.11.2016, leg. B. Sirenko; stn. 5, 19 ° 38 ’ 12 ’’ N, 111 ° 01 ′ 52 ’’ E, intertidal, on stones, 3 spms, BL 3.0 – 4.0 mm, 14.11.2016, leg. B. Sirenko; stn. 13, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, depth 2 – 3 m, on old corals, 2 spms, BL 4.0 mm, 19.11.2016, leg. B. Sirenko; stn. 14, 18 ° 12 ’ 09 ’’ N, 109 ° 29 ′ 40 ’’ E, intertidal pool, on stones, 1 spm, BL 4.0 mm, 19.11.2016, leg. B. Sirenko; stn. 22, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ’ 40 ’’ E, depth 2 m, on old corals, 1 spm, BL 3.0 mm, 21.11.2016, leg. B. Sirenko; stn. 26, 18 ° 11 ’ 46 ’’ N, 109 ° 29 ’ 40 ’’ E, intertidal – 1.5 m, on stones, 21 spms, BL 2.0 – 4.0 mm, 22.11.2016, leg. B. Sirenko, S. Grebelniy.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F05FF7AC198FD25FE64.taxon	distribution	Distribution. Vietnam from the Gulf of Thailand to Danang, China, Hainan Island, mainly intertidal to 3 m depth.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8A9F05FF7AC198FD25FE64.taxon	discussion	Remarks. This is one of the abundant species of the intertidal zone which is difficult to find because of its small size and the rich fouling on the valves.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8B9F05FF7AC017FE15F859.taxon	materials_examined	Type species. Chiton coarctatus Sowerby, 1841, by monotypy. Genus distribution and range. Japan, Hong Kong, Vietnam, Coral Sea (Capel Bank, 25 ° 20´S, 159 ° 44´E), intertidal to 56 m. Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8B9F05FF7AC57EFC7AFC82.taxon	materials_examined	Type species. Placiphorella velata Carpenter MS, OD Dall 1879. Genus distribution and range. NW and NE Pacific Ocean (shallow water species, from intertidal zone to 60 m depth), Pacific Ocean, from the Bering Sea to New Zealand and Chile, South Indian Ocean and North Atlantic Ocean (deep-water species, from depth 100 to 2000 m). Miocene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8B9F05FF7AC450FE76FA6B.taxon	description	(Fig. 4 B)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8B9F05FF7AC450FE76FA6B.taxon	description	1994: 308; Saito 1995: 107; 1998: 153; 2000: 17, pl. 8, fig. 7; 2001: 199, fig. 13; 2006: 215; 2017: 53, 736, pl. 9, fig. 5; Xu 2008: 458. Non: Placiphorella stimpsoni; Dall 1886 (pars) et auct. (= Placiphorella borealijaponica Saito & Okutani, 1989). Non: Placiphorella stimpsoni; Dall 1921: 197; Oldroyd 1927: 316. (= Placiphorella velata Carpenter MS, Dall, 1879).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8B9F05FF7AC450FE76FA6B.taxon	materials_examined	Type material. Syntypes USNM 1646. Type locality. Japan, Hakodadi Bay, 45 m. Material examined. South China Sea, Hainan Island, Sanya, 55 M- 443, 1 spm, BL 25.0 mm, 0 6.04.1955 Distribution. Japan, southern and western shores of Korea, Taiwan, Hong Kong and Hainan. Remarks. For a long time it was believed that this species occurs in the sea of Japan and near Hokkaido (Is. Taki 1938; Jakovleva 1952; Sirenko 1976 b). However, Saito & Okutani (1989) found another species P. borealijaponica occurs there.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF889F07FF7AC7A1FD47F951.taxon	description	(Figs 19 – 21)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF889F07FF7AC7A1FD47F951.taxon	description	“ Notoplax ” doederleini; Saito 1998: 160, fig. 2 N; 2000 a: 102. Leptoplax doederleini; Saito 2000: 21, pl. 10, fig. 6; 2001: 200, fig. 14; 2006: 217; 2017: 54, 737, pl. 10, fig. 8; Sirenko & Saito 2017: 460, figs 9 – 12, 43 D. Type material. Holotype ZMB Moll. 102017.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF889F07FF7AC7A1FD47F951.taxon	materials_examined	Type locality. Kajiyama (=? Katsuyama, Tokyo Bay), Japan. Material examined. South China Sea, Hainan, Xincun, corals and Zostera sp., 0.5 m, 1 spm, BL 10.5 mm, 21.04.1958.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF889F07FF7AC7A1FD47F951.taxon	distribution	Distribution. From Pacific coast of central Japan to Okinawa, Hong Kong, Hainan and northern Vietnam, 0 – 20 m.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF889F07FF7AC7A1FD47F951.taxon	discussion	Remarks. Van Belle (1982) reported this species from Hong Kong for the first time. Specimens from Hainan (Fig. 20 D, this study) and from Vietnam (Fig. 11, Sirenko & Saito 2017) differ from specimen from specimens from Hong Kong (Fig. 4, Van Belle 1982) by the shape of the central tooth of the radula. The studied specimen (BL 10.5 mm) has a radula that is 3.5 mm long with 37 transverse rows of mature teeth and 11 gills extended from valve V to valve VII. Slit formula of this specimen is 5 / 1 / 8.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF899F07FF7AC025FD72F82A.taxon	materials_examined	Type species. Chiton fascicularis Linnaeus, 1767, by monotypy. Genus distribution and range. Widespread in tropical and subtropical waters of all oceans and seas, from the intertidal zone to shallow water. Oligocene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8E9F00FF7AC2B2FE75F806.taxon	materials_examined	Type material. Lectotype MCZ 169031. Type locality. Kikaia and Hakodadi (= Hakodate) Bay, Hokkaido, Japan	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8E9F00FF7AC2B2FE75F806.taxon	distribution	Distribution. Japanese coast from southern Hokkaido to Okinawa Island; Korean coast; East China Sea Coast of China; South China Sea, Hong Kong, northern Vietnam, intertidal.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8E9F00FF7AC2B2FE75F806.taxon	discussion	Remarks. Bullock & Harper (1994) reported this species from Hong Kong for the first time, but they identified it as Notoplax doederleini (Thiele, 1909). Their good description and figures show that their identification was erroneous.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC7A1FE13FC93.taxon	description	(Fig. 4 C)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC7A1FE13FC93.taxon	materials_examined	Type material. Holotype ZISP 2179. Type locality. South China Sea, off South Vietnam, Nhatrang Bay, Nok Island. Material examined. South China Sea, Hainan Island, Xincun, Nanwanhou Island, rocks, 1 spm, BL 8.0 mm, 20.04.1958.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC7A1FE13FC93.taxon	distribution	Distribution. South China Sea, Vietnam from Nhatrang Bay to Da Nang, and China, Hainan and Hong Kong, intertial – 0.5 m.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC7A1FE13FC93.taxon	discussion	Remarks. Van Belle (1980) reported this species from Hong Kong for the first time, but he identified it as Notoplax (Notoplax) formosa (Reeve, 1847). Later Van Belle (1982) changed his identification into Notoplax (Notoplax) sp. Bullock & Harper (1994) followed Van Belle (1980). Owing to the good drawings of Piet Kaas in Van Belle (1982), the good figures and description of Bullock & Harper (1994), we identify this species as Acanthochitona britayevi.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC460FD32FAC7.taxon	description	(Figs 4 D, 22 – 24)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC460FD32FAC7.taxon	description	Acanthochiton sp.; Xu 2008: 458.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC460FD32FAC7.taxon	materials_examined	Type material. ITZ. Type locality. Sanguisiapo, Banda, Indonesia (“ Siboga ” Expedition, stns. 93, 240, 0 – 12 m). Material examined. South China Sea, Xisha Islands, MBM 100328, 2 spms, BL 12.0 – 14.0 mm, 20.04.1958	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC460FD32FAC7.taxon	distribution	Distribution. Indonesia, Xisha Islands, Japan (Amami Islands).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F01FF7AC460FD32FAC7.taxon	discussion	Remarks. The studied specimen (BL 14 mm) has a radula that is 4.5 mm long with 33 transverse rows of mature teeth and 14 gills extended from valve IV to valve VII. The species has previously been reported from Indonesia (Nierstrasz 1905) and South Japan (Saito 2000). Due to the new record from Xisha Islands, the geographic range for this species is expanded.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F02FF7AC29FFA95FF69.taxon	description	(Fig. 4 E)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F02FF7AC29FFA95FF69.taxon	materials_examined	Type material. Holotype ZISP 2233. Type locality. South China Sea, Near Da Nang, central Vietnam, 16 ° 11´2.22 ’’ N, 108 ° 10´35.58 ’’ E, intertidal, on barnacles. Material examined. South China Sea, Hainan Island, stn. 1, 20 ° 09 ’ 36 ’’ N, 110 ° 41 ′ 17 ’’ E, depth 1 – 3 m, on stones, 1 spm, BL 5.0 mm, 12.11.2016, leg. B. Sirenko, S. Grebelniy.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F02FF7AC29FFA95FF69.taxon	distribution	Distribution. Southern to northern Vietnam, from Nhatrang Bay to Cat Ba (12 ° 41.037´N to 20 ° 47.090´N), and China, Hainan and Hong Kong, intertidal – 7 m.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FF8F9F02FF7AC29FFA95FF69.taxon	discussion	Remarks. Van Belle (1980) reported this species from Hong Kong for the first time, but he identified it as Craspedochiton laqueatus (Sowerby, 1841), which was followed by Bullock & Harper (1994). Their figures and short description of this species show that it is not a Craspedochiton, but an Acanthochitona. Moreover, they reported that this species “ was by far the most abundant acanthochitonid collected at Cape d’Aguilar ”. As far as we know, species of Craspedochiton are never abundant. This is the first find of A. lanae from Hainan Island.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3CFF7AC7E8FAFAFEF3.taxon	materials_examined	Type species. Cryptoconchus larvaeformis de Blainville MS, Burrow, 1815, SD Gray 1821. Genus distribution and range. Tropical and subtropical waters of the Indo-Pacific. Paleogene – Recent.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3CFF7AC683FB47FCB5.taxon	materials_examined	Type material. Holotype ANSP 77308. Type locality. Samoa, Upolu Island, Apia (13 ° 48 ’ S, 171 ° 44 ’ W). Distribution. Samoa, Marshall, New Caledonia islands, Indonesia, Japan, China and Queensland, Australia (Schwabe et al. 2008). Remarks. This species was collected from China for the first time at Xisha Islands (Ma 2004).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3CFF7AC441FE3DFAD9.taxon	description	(Fig. 4 F)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3CFF7AC441FE3DFAD9.taxon	materials_examined	Type material. Holotype NHM 1951.1.28.1. Type locality. Unknown. Material examined. South China Sea, Xisha Islands, 57 – 419, 1 spm, BL 35.0 mm, 12.06.1957. Distribution. Andaman Sea, Xisha Islands, Japan, Philippines, Samoa, New Caledonia and Australia (Schwabe et al. 2008).	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3DFF7AC2AAFD4BFE19.taxon	description	(Fig. 4 G)	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3DFF7AC2AAFD4BFE19.taxon	materials_examined	Type material. Neotype (ZSM Mol 20062203), designated by Schwabe (2007). Type locality. Indonesia, Irian Jaya, North side of Jeftsiep Island (0 ° 21 ’ 51 ’’ N, 130 ° 17 ’ 46.8 ’’ E), 2 – 3 m depth. Material examined. South China Sea, Xisha Islands, 57 – 419, 1 spm, BL 32.0 mm, 09.041957; Hainan, Luhuitou, dead corals, intertidal, 1 spm, BL 51.5 mm, 25.03.1958, leg. O. Scarlato; Xincun, corals, 1 spm, BL 30.0 mm, 18.04.1958; Sanya, corals, 1 spm, BL 33.0 mm, 31.04.1958. Xinying, rocks, intertidal, 1 spm, BL 62.0 mm, 10.05.1958.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3DFF7AC2AAFD4BFE19.taxon	distribution	Distribution. The species is distributed in the South China Sea along coast of Vietnam from Phu Quy Island to Dat Island, near Hainan and Xisha Islands, near Okinawa Islands, Indonesia and Philippines from intertidal zone up to 8.0 m depth.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
411A87B3FFB29F3DFF7AC2AAFD4BFE19.taxon	discussion	Remarks. Since Kaas & Van Belle (1980), this species had been considered as junior synonym of C. larvaeformis until Schwabe (2007) designated a neotype and published a detailed redescription of C. oculata. The latter species can easily be distinguished from C. larvaeformis and other species of the genus Cryptoplax by having a black ring of spicules around the first three valves.	en	Sirenko, Boris I., Zhang, Junlong (2019): Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea. Zootaxa 4564 (1): 1-40, DOI: 10.11646/zootaxa.4564.1.1
