(Sakai, 1938)
Carapace subpentagonal; the dorsal surface covered with asteroidal granules, corresponding to fused mushroom-like ornaments. On dorsal and ventral surfaces of the carapace, twelve eroded grooves containing visible mushroom-shaped granules. Antero-lateral borders armed with two denticles; postero-lateral borders with one in the middle; at their junction a stout denticulated process. Rostrum declivious, median lobe narrow, its tip armed with three denticles; dorsally, a small denticle. Chelipeds stout but scarcely longer than carapace, greatly unequal in both sexes, finger tips pointed. Ambulatory legs compressed; P1-P5 all articles (dactyl excepted) spiny. (Guinot 1998)
Type locality: coast of Tatsugahama, Kii, Japan.
Range: Japan - Tatsugahama (Sakai, 1938a), Sagami Bay, Kii Minabe and Tosa Bay (Sakai, 1965b), Sagami Bay, Kii Nagashima, Kii Minabe, Tatsugahama and Tosa Bay (Sakai, 1976a), Ogasawara-shoto (Takeda & Kurata, 1976b), Wagu (Ng & Tan, 1999); Philippines - north of Lubang Island (Serène & Vadon, 1981); Hawaiian Islands - Oahu (Ng & Tan, 1999).