Stimpson, 1857
Carapace subcircular and thickly covered with velvet-like tomentum; in the young specimen, however, the carapace seems rather rhomboidal, as the pseudorostral, epibranchial and intestinal spines are proportionally more projecting than those of the adult. The gastric region is armed with four median tubercles, of which one posterior is erect and spiniform; on either side of this row are two low tubercles. The cardiac region has an erect median spine, between it and the posterior gastric spine is another low tubercle. The intestinal spine is very long and horizontally projected backwards. The hepatic region scarcely convex, having a small tubercle. The branchial region has three marginal spines, two anterior are small, while the last one is very prominent and pointed obliquely backwards. The epibranchial region is mounted with two indistinct tubercles, the mesobranchial region with four, arranged in an oblique row, and also a tubercle on either side of the cardiac region.
The pseudorostrum is narrow, horizontally produced, bifid in the distal half, the median sinus being very narrow. No preocular spine at all, the postocular cup pointed at the tip. Basal segment of antenna is armed distally with a large tooth, the flagellum being very slender and short. A very long spine at the outer side of the green gland, which corresponds to the infraorbital tooth; the antero-external angle of the buccal cavern is produced into a prominent spine. The pterygostomial region has two spines, of which the anterior one is very small, while the other is very large and is visible from dorsal side; this region is characterized in having a hairy channel extending along the buccal frame.
Chelipeds are short and slender, each segment being cylindrical and covered with tomentum, fingers alone are naked. Ambulatory legs are rather stout, the dactylus naked and strongly compressed.
Abdomen of both sexes seven-segmented. (Sakai, 1938: 282)
Type locality: off Tamtoo Island near Hong Kong.
Range: India - Hooghly River and Orissa Coast (Alcock, 1895a), north-east of Bay of Bengal (Griffin, 1974); Arakan Coast (Alcock, 1895a); Andaman Sea (Griffin, 1974); Malaysia - Pinang (Lanchester, 1902); Japan - Kii Tatsugahama, Gobo and Tosa Bay (Sakai, 1938a), Kii Nagashima, Kii Minabe, and Tosa Bay (Sakai, 1976a), Tosa Bay (Miyake, 1983), Kagoshima Bay; Taiwan - Tingch'ieting (Lin, 1949); China - Hong Kong (Stimpson, 1857c), Wenzhou and Fuzhou (Shen, 1940b), Guangxi, Guangdong including Hainan Island and Fujian (Dai & Yang, 1991); Singapore (Nobili, 1903c); Java Sea.