Stimpson, 1858
Carapace convex and smooth, regions ill defined. Frontal breadth less than one-third the breadth of the carapace, cut into 2 lobes by a V-shaped median notch; anterior border of lobe slanting postero-laterally. Antero-lateral margin composed of 4 teeth, excluding the outerorbital angle; first two broadly triangular, the second larger than the first, the third also larger and sharper, the last one small but acute. Postero-lateral margin straight. Posterior margin somewhat convex.
Chelipeds quite asymmetrical. Merus shortly triquetrous and with short hairs along the dorsal margin. Carpus convex and also bearing short hairs at the inner-distal angle. Palm with microscopic pits on the outer surface and smooth on the inner surface. Finger shorter than the palm; the movable finger of the larger chela with small obtuse teeth along the cutting edge; the immovable finger with 1 large tooth and 2-3 small ones. Ambulatory legs also furnished with short hairs; propodus and dactylus also armed with brushy hairs along the anterior and posterior margins.
First pleopod of the male stout and with the distal portion broadened, apex obliquely truncated. Male abdomen narrow and long, 7-segmented; telson semicircular. Carapace length of the male 13.3 mm, breadth 17.6 mm; of the female, length 13 mm, breadth 17.4 mm. (Dai & Yang, 1991)
Type locality: Hong Kong.
Range: Red Sea (Klunzinger, 1913); Mozambique - (Crosnier, 1984), Delagoa Bay (Barnard, 1947, 1950); Madagascar; Japan - Kobe (Miers, 1886), Tokyo Bay (Ortmann, 1893), Sendai Bay, Yokohama and Ise Bay (Sakai, 1939), Sagami Bay (Sakai, 1965b), Sendai Bay, Yokohama, Sagami Bay, and Ise Bay (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Yamagata Prefecture (Suzuki S., 1979), Kii Nagashima (Miyake, 1983), Oga Peninsula, Kamakura, Enoshima, Shimoda, Kii Nagashima, and Tosa Bay (Muraoka, 1998); Korea - Inch'on (Sakai, 1939), Keisho-nando, Zenra-nando and Keiki-do (Kamita, 1941), Daecheon, Odong Island, Jang-gun Island, Bang jugpo, Impo, Namhae Island, Gyeogpo Ri, and Eocheong Island (Kim, 1970, 1973); China - Hong Kong (Stimpson, 1858a, 1907), Qingdao (Shen, 1936), Shaotsun, Pingtan, Guantao, and Xiamen, Fujian Province (Shen, 1940b), Guangdong, Fujian, Zhejiang and Shandong Peninsula (Dai & Yang, 1991); Taiwan; Gulf of Thailand; Singapore (Muraoka, 1998); Philippines - Catbalogan, off western Samar (Garth & Kim, 1983); Hawaiian Islands - Honolulu (Rathbun, 1894c, 1906); low tidal marks