(Miers, 1879)
Carapace pentagonal, broader than long. Surface of frontal, epi- and metabranchial regions, the middle part of the gastro-cardiac regions and the carina of the posterior margin coarsely granulated, rest of the surface smooth. The lateral part of the metagastric region and the center of the cardiac region with a granulated protuberance, from which a ridge extends to the postero-lateral margin. Middle part of frontal margin concave. Antero-lateral margin not very straight, posterior part slightly arched, posterior end forms an acute angle. Anterior one-third part of the postero-lateral margin protruding, posterior two-thirds concave. Posterior border carinate, with two semicircular lobes, lowered in position.
Chelipeds stout. Merus with coarse granules on upper and inner borders, posterior border and posterior surface coarsely granulated proximally. Ambulatory legs compressed, surface granulate.
Abdomen of the female large and rounded. (Dai & Yang, 1991)
Type locality: Japan.
Range: Japan - (Miers, 1879b), Kii Peninsula and Osaka Bay (Sakai, 1965b, 1976); China - Hainan Island (Dai & Yang, 1991).