(Alcock, 1895)
Carapace regularly triangular, the dorsal surface mostly smooth but scattered with a few granules near the postero-lateral borders; the regions are deeply delimited. There are two conical stout tubercles in the median line of the carapace, one of which occupies the centre of the gastric region and the other that of the cardiac region and is followed by a small tubercle immediately behind it; also a stout conical tubercle is found in the centre of the branchial regions. The intestinal region is marked with a small tubercle in the middle.
The rostrum trilobate, declivous, the supraocular eave sensibly thickened, the postocular lobe not projecting beyond the eyes, behind which the postocular constriction is somewhat pronounced. The hepatic lobe prominent, armed with a large tooth and two smaller ones. The antero-lateral border behind the hepatic lobe is closely festooned by a row of about 7 sharp laciniated teeth, the bases of which are fused together, and the last one is predominant in size, projecting obliquely backwards and bearing 4 or 5 laciniated teeth. The pterygostomial regions, as also the exposed surface of sternum and of external maxillipeds are covered with granules.
Chelipeds of our male specimen are unequal and indistinctly covered with granules; merus with its anterior border armed with three large and eight to nine smaller teeth, the posterior border irregularly granulated; wrist unarmed excepting a few tubercles; palm distally thickened, its outer border with two or three obtuse processes and its inner border, together with the upper border of the movable finger, irregularly denticulated. Ambulatory legs are very slender and depressed; the merus with its anterior and two (upper and lower) posterior borders denticulated; carpus and palm are also denticulated along the anterior border only or both anterior and posterior borders.
Abdomen is thickly covered with granules, which are disposed in transverse series. (Sakai, 1938: 337)
Type locality: off Sri Lanka.
Range: Mauritius (Michel, 1964); Sri Lanka (Alcock, 1895a); Andamans (Alcock, 1895a); Japan - (Flipse, 1931), between Ito and Hatsushima (Sakai, 1938a), Sagami Bay (Sakai, 1965b), Sagami Bay and Tosa Bay (Sakai, 1976a), Shiono-misaki (Takeda, 1979a).