(de Haan, 1833)
(Monotypic, thus generic description repeated):
Carapace quadrangular, surface convex in both directions, without ridges or elevations, evenly hairy with short, dark pubescence; antero-lateral borders without teeth behind external orbital angle. Chelipeds homochelous, with clear sexual dimorphism; male chela with single molariform tooth on cutting edge of dactylus, no one on immovable finger; female chelae without any teeth on fingers. Meri of second to fifth pereiopods without spines. Abdomen of male with second to fourth segments fused, gradually tapering towards terminal segment so that the gonopods are completely covered when abdomen is pressed against thorax; first segment very wide reaching the coxae of fifth pereiopods. Male first pleopod gradually tapering to tip, without long distal appendages, subdistal fungiform bristles are present. (Türkay 1995)
Type locality: Japan.
Range: Japan - (de Haan, 1833), Tokyo Bay (Ortmann, 1894a), Ariake Bay (Sakai, 1939, Miyake, 1961), Saga Prefecture and Shimabara Peninsula (Sakai, 1976a), Shirakawa, Kumamoto (Miyake, 1983); Korea - (Sakai, 1939), Heian-hokudo, Heian-nando, Kokai-do, Keiki-do, Chusei-nando, Zenra-nando, Zenra-hokudo and Keisho-nando (Kamita, 1941), Hae-undae, Mogpo, Juan, Inch'on, and Seondu Ri (Kim, 1973), Yellow Sea side (Sakai, 1976a); China - Liaodong Peninsula, Bo Hai, and Shandong Peninsula (Shen, 1932), Dairen (Sakai, 1939), Guangdong and Fujian (Dai & Yang, 1991).