(de Haan, 1837)
Carapace somewhat depressed and the dorsal surface covered with vesicular granules, each of which is furnished with a few curled hairs; the regions are ill-defined. There are five long spines in the median line of the carapace, three being gastric, one cardiac and one intestinal; on the posterior margin are placed two small spines side by side. The true rostral spine is prominent and projects forwards and downwards. The pseudorostral spines are cylindrical and very long, being more than one fourth as long as the remainder of the carapace, they are moderately divergent and directed obliquely upwards. The supraocular eave very thick and its posterior angle produced into a prominent spine, the tip of which is curved upward; there is no preocular spine at all. Intercalated spine slender, the postocular spine very long and acuminate, projecting horizontally outwards and forwards, having an accessory spinule at the base of the inner border. Behind the postocular spine follows a marginal row of five spines, one hepatic and the others branchial; they are very long and project outwards and upwards, inside the last of which is a curved row of two dorsal spines.
Subhepatic and epimeral regions are armed with erect spinules; the basal antennal segment is armed with a proximal spine on the outer border and with two larger terminal spines, one ventral and the other lateral. Infraorbital lobe present, its tip being subtruncate.
Chelipeds of full-grown male are very smooth and slender, the palm is inflated and the fingers gape at the base, the movable finger being armed with a subbasal tooth. The ambulatory legs are covered with very long yellowish hairs. The merus of each pair has a long spine at the distal end of the upper border.
Abdomen of both sexes composed of seven distinct segments. (Sakai, 1938: 297)
Type locality: Japan.
Range: Pakistan (Alcock, 1895a); Japan - (de Haan, 1837), Tokyo Bay (Ortmann, 1893), Manazuru (Sakai, 1935), Sagami Bay, Nanki Shirahama and Amakusa (Sakai, 1938a), Sagami Bay (Sakai, 1965b), Sagami Bay, Manazuru, Wagu, Kii Nagashima, Kushimoto, Shiono-misaki, Kii Minabe, Shimogusui, Tosa Bay, and Amakusa (Sakai, 1976a), Kushimoto (Miyake, 1983); Korea - Cheju-do (Kim, 1973); Taiwan (Lin, 1949, Dai & Yang, 1991); 15-50 m.