Onithochiton cf. hirasei Pilsbry, 1901 (Fig. 3D) Onithochiton hirasei Pilsbry 1901: 203; Huang & Xu 1964: 10; Wu 1969: 109, figs 6, 59–67; Kaas & Van Belle 1980: 59; 1998: 90; Bullock & Harper 1994: 34, pls. 8F, 11A–C, 12A, B; Saito 1998: 156; 2000: 21, pl. 10, fig. 13; 2006: 214; 2017: 51, 735, pl. 7, fig. 10; Hasegawa et al. 2001: 4; Ma 2004: 6, pl. 2, fig. H; Kaas et al. 2006: 389, fig. 166, map 63 (bibliography and synonymy); Xu 2008: 457; Zhang et al. 2015: 101, fig. 8. Onithochiton (Onithoplax) hirasei; Is. Taki 1962: 47; Iw. Taki 1964b: 412. 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. Distribution. Japan, Korea, Taiwan, Guangdong Province and Hainan Island. 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.

Published as part of Sirenko, Boris I. & Zhang, Junlong, 2019, Chitons (Mollusca: Polyplacophora) of Hainan Island and vicinity, South China Sea, pp. 1-40 in Zootaxa 4564 (1) on pages 19-21, DOI: 10.11646/zootaxa.4564.1.1, http://zenodo.org/record/2588445