(de Haan, 1835)
The entire body devoid of hairs; the carapace moderately deepish but the hepatic and postero-lateral surfaces are depressed, the latter defined with an oblique ridge extending from the third tooth of the antero-lateral border to the base of the last ambulatory leg. The front is a little less than half the width of the carapace, the free margin is entire and moderately expanded anteriorly. There are three teeth on the antero-lateral borders, the first or the external orbital angle and the second one are subequal, the third one somewhat smaller. The infraorbital fidge is entire, microscopically striate, and becomes narrower externally. Chelipeds are symmetrical, the wrist has an obtuse tooth at the inner angle, the palm is swollen and the movable finger of adult male has a fleshy protuberance at the base between it and the immovable finger. The dactylus of ambulatory legs is compressed and distinctly shorter than the propodus, having six longitudinal rows of short blackish setae around the whole surface. (T. Sakai, 1939: 672)
Type locality: Japan.
Range: Sakhalin; Japan - (de Haan), Tokyo Bay, Sagami Bay and Nagasaki (Ortmann, 1894a), Tokyo, Misaki, and Wakanoura (Rathbun, 1902a), Mutsu Bay (Yokoya, 1928), Shimoda (Sakai, 1935), Akkeshi, Mutsu Bay, Kesen-gun, Tateyama Bay, Misaki, Shimoda, Ise Bay, Gobo, Tosa Bay, Miyazaki and Nagasaki (Sakai, 1939), Sagami Bay (Sakai, 1965b), from Akkeshi, Hokkaido to Kyushu and Okinawa (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Yamagata Prefecture (Suzuki S., 1979), Nanki Shirahama (Miyake, 1983), Oshoro, Shakotan, Kikonai, Hakodate, Usu, off Hiroo, Akkeshi, and Rishiri (Komai et al., 1992), Soya Strait (Takeda & Miyauchi, 1992); Korea - Jinsen (Sakai, 1939), Kankyo-hokudo, Kankyo-nando, Kogen-do, Keisho-hokudo, Keisho-nando, Zenra-nando, Zenra-hokudo, Chusei-nando, Keiki-do and Kokai-do (Kamita, 1941), East Sea, Korea Strait, Cheju-do, and Yellow Sea (Kim, 1973), Cheju-do (Kim & Chang, 1985); China - Hong Kong (Stimpson, 1907), Liaodong Peninsula, Bo Hai Gulf, and Shandong Peninsula (Shen, 1932), Tsimei, Fujian Province (Shen, 1940b), Guangdong, Fujian, Zhejiang, Jiangsu, Shandong Peninsula, Bohai Bay and Liaodong Peninsula (Dai & Yang, 1991); Taiwan - Tan-shui (Sakai, 1939, Lin, 1949); between high and low tidal marks.