Stimpson, 1858
Carapace strongly convex, its width across the branchial regions very near to its length; branchial regions with short, closely set granular ridges or rugae, and single granules visible to the naked eye, these are separated by granular interspaces; median area appearing smooth, but evenly covered with microscopic granules and numbers of scattered groups of larger granules regularly disposed over the surface; a pair of rounded tubercles present between anterior portions of the branchial regions; regional grooves well defined; antero-lateral spines small, recurved; posterior truncated border nearly straight, not produced beyond the abdomen. (Türkay 1995)
Type locality: Hong Kong.
Range: Japan - Okinawa (Stimpson, 1907), Amami-Oshima and Okinawa (Sakai, 1976a), Tanegashima (Takeda, 1976b), Ishigaki-jima (Miyake, 1983), Okinoerabu-jima and Yoron-jima (Muraoka, 1998), Okukubi River, Okinawa (Shokita et al., 1998); Taiwan - Tan-shui (Sakai, 1939, Lin, 1949), Tan-shui River, Lu-Kang, Wen-Kang and Chi-Gu (Huang et al., 1992); China - Hong Kong (Stimpson, 1858b, Ortmann, 1894a), Hainan Island (Shen, 1936), Tsimei and Hainan Island (Shen, 1940b), Guangxi, Guangdong including Hainan Island and Fujian (Dai & Yang, 1991); Singapore (Ortmann, 1894a); Indonesia - Karakelong, Ambon and Bawean Island (Tesch, 1918a).