(Miers, 1876)
Carapace very broad (breadth just over 2-2 1/3 times length); surface finely granulated; usually with recognizable mesogastric, epibranchial, and indistinct metagastric ridges, cardiac and mesobranchial ridges with low granular eminences; front with 2 acute teeth; antero-lateral borders with 9 teeth, last one very large and projecting straight out laterally; postero-lateral junction rounded. Cheliped merus with postero-distal border spinous, anterior border with 3-4 (usually 4) sharp spines; carpus with inner and outer spines; lower surface of palm smooth. Posterior border of swimming leg without spines or spinules. (Türkay 1995)
Postero-lateral junction of carapace rounded; antero-external angle of merus of third maxilliped not produced laterally; 2 frontal lobes; carapace very broad, breadth almost twice length, covered with fine granules. (Davie 1999)
Type locality: Japan.
Range: Japan - (de Haan, 1835, Miers, 1876a, Parisi, 1916), Tokyo Bay (Ortmann, 1893), Yokohama and Yokosuka (Parisi, 1916), Mutsu Bay (Yokoya, 1928), Inubo-zaki and Kinkazan (Yokoya, 1933), Shimoda (Sakai, 1935), Mutsu Bay, Tokyo Bay, Sagami Bay, Ise Bay and Nagasaki (Sakai, 1939), Sagami Bay (Sakai, 1965b), Mutsu Bay, Inubo-zaki, Tokyo Bay to coast of Nagasaki, Hachiro-gata, Tsuruga and Yonago (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Yamagata Prefecture (Suzuki S., 1979), Oshoro, Ueiso, Muroran, and Otanoshike, Hokkaido (Komai et al., 1992), Okinawa; Korea - (Kamita, 1941), Aninjin, Seogwipo, Daeheugsan Island, Bi-geum Island, Wido Island, Eocheong Island, Daecheon, Anmyeon Island, Ganghwa Island, Deogjeog Island, and Yeong-jong Island (Kim, 1973); China - Liaodong Peninsula, Bo Hai, and Shandong Peninsula (Shen, 1932), Hong Kong, Macao and Hainan (Shen, 1931a), Shanghai, Haimen, Fuzhou, Santuao, Tsimei, Liuwutien, and Xiamen (Shen, 1940b), Shanghai (Stephenson, 1972a), Guangxi, Guangdong, Fujian, and Zhejiang (Dai & Yang, 1991); Taiwan - Tan-shui (Lin, 1949), P'eng-hu and Yüan-lin Province (Huang & Yu, 1997); Palau (Takeda & Shimazaki, 1974); 10-30 m.