de Haan, 1835
Carapace slightly broader than long, pentagonal in outline; surface convex, every region covered with isolated tubercles of various sizes; tubercles on anterior dorsal half flattish, while tubercles on posterior half somewhat cauliflower-like, spaces between tubercles covered with short tomentum. Front produced, margins elevated; anterior margin truncated, divided into 2 lobes by a longitudinal median groove, the outer margin of each lobe separated by a deep notch from the inner angle of orbit. Dorsal orbital margin slanted postero-laterally, armed with obtuse processes. Antero-lateral margin with 3 fairly large flat tubercles or bluntly coniform processes. Postero-lateral margin bearing a few tubercles, of which the formost is more prominent. P1 symmetrical. Carpus covered with more than 10 flat tubercles or round-blunt processes on the dorsal surface and with a longitudinal granular row composed of fine granules and posterior margins, dactylus slender and elongate. Male Pl 1 elongate, distal half more slender and distal end curved inner-dorsally. Male abdomen narrow and long, abdominal segment 6 squarish; terminal segment elongately triangular. Male carapace length/breadth 20.3-25.6/25.6-31.9, female 23.2/28.9. Habitat: muddy or sandy-muddy bottom, 20-50 m deep. (Dai & Yang, 1991: 264)
Type locality: Japan.
Range: Japan - (de Haan, 1835), Shimoda (Sakai, 1935), Ise Bay, Onomichi, Miyazaki Prefecture and Nagasaki (Sakai, 1939), Sagami Bay, Ise Bay, Onomichi, coast of Miyazaki Prefecture and Nagasaki (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Yamagata Prefecture (Suzuki S., 1979), Mikawa Isshiki, Tosa Bay, Nagasaki and Miyazaki (Muraoka, 1998), off Honshu, Tosa Bay and Amakusa (Galil, 2000), off Matsuyama, Seto Inland Sea (Takeda et al., 2000); Korea - Pusan Bay (Kamita, 1941); Taiwan - Hsiak'unhsen and Tingch'ieting (Lin, 1949), Tashi, I-Lan County (Galil, 2000); China - Hong Kong (Stimpson, 1907, Galil, 2000), Hainan Island (Dai & Yang, 1991); New Caledonia (A. Milne Edwards, 1867); 20-50 m.