(Kubo, 1936)
This species may easily be distinguished from its congeners in the following constant characters:
The carapace behind the orbital region is almost circular and its dorsal surface covered with large wart-like tubercles. There are no spines in the median line, nor on the margins of the carapace. The pseudorostral spines are slender and not very long, less than one fourth the remainder of the carapace, their tips being slightly divergent and their bases being fringed with long hairs. The three orbital teeth are basally broad and are acuminate at tip, the postocular one being most prominent.
The basal segment of antenna is armed with two distal spines, but without any basal tooth on the outer border. Chelipeds are smooth and naked as usual, the palm of male slightly swollen but the fingers unarmed. Ambulatory legs are thickly covered with coarse hairs, each segment being cylindrical. (Sakai, 1938: 300)
Type locality: Kominato, Boso Peninsula, Japan.
Range: Japan - Kyushu (Sakai, 1938a), Boso Peninsula, Tosa Bay and Danjo-gunto (Sakai, 1976a), Kumano-nada (Miyake, 1983).