Stimpson, 1858
Carapace is broadly trapeziform, the antero-lateral borders are markedly divergent backwards; a narrow triangular facet is defined on either postero-lateral portion of the carapace by an oblique ridge extending from the middle of the antero-lateral border to the postero-lateral border near the base of the last ambulatory leg. The dorsal surface of carapace is naked but toward the margins, it is covered with pubescence. The front as broad as the extreme width of orbit, subtruncate but medially marked by an obscure groove; the eyestalks are of good length. The ischium of the external maxilliped is basally very broad and somewhat longer than the merus; the dactylus of palp is oblong and cylindrical, jointed at the tip of the propodus. The cheliped of male is very stout, the palm is a good deal higher and its superior border crested; the immovable finger is unarmed and basally arcuate; the movable finger bears an obtuse tooth near the middle. The chelipeds of female are very slender and the fingers not gaping. The second pair of ambulatory legs are longest, the third pair a little shorter, the merus of these pairs is very stout and covered with tomentum but the succeeding segments are slender. The first pair is markedly slender and the last pair much more reduced in size. (T. Sakai, 1939: 601)
Type locality: off Sendai Bay, Japan, 38°N, 54 m.
Range: Japan - Sendai Bay (Stimpson, 1858b), Mutsu Bay (Yokoya, 1928), Mutsu Bay, Onagawa Bay and Osaka Bay (Sakai, 1939), Sagami Bay (Sakai, 1965b), Izu Peninsula, Mikawa Bay, Seto-Naikai (de Man, 1907), Ariake-kai (Miyake, 1961), Mutsu Bay, Sagami Bay, Mikawa Bay, and Osaka Bay (Sakai, 1976a), Otsuchi Bay, Iwate Prefecture (Takeda & Konishi, 1991); East China Sea (Takeda & Miyake, 1968c); 10-65 m.