Rathbun, 1932
Carapace with regions well defined, usually with tubercles or short spines; postorbital lobe keeled or laterally flattened; hepatic and postorbital lobes partly fused; postorbital lobe much smaller than hepatic spine; branchial submargin with tubercles; rostrum more than 1/3 postrostral carapace length; hepatic and branchial margin each with a slender, acuminate spine; dorsal surface of carapace even and smooth. (Davie 1996)
Type locality: Omae-zaki Light, Japan.
Range: Japan - Sagami Bay, Shimoda and coast of Wakayama (Sakai, 1938a), Sagami Bay, Suruga Bay, Mikawa Bay, Shima Peninsula, and Kii Peninsula (Sakai, 1976a), off Nojima-zaki, Boso Peninsula (Takeda, 1981a).