Sakai, 1938
Carapace behind the orbital region is rounded triangular, the regions are defined by deepish grooves. The gastric region is mounted with four tubercles in the median line, followed by two small ones side by side on the posterior slope; on protogastric region, not far behind the orbit are placed two large tubercles side by side; and lastly four or five tubercles, one of which is high, on either side of the fourth median gastric tubercle. In the interval between the gastric and cardiac regions are three low tubercles, of which two are placed side by side in front of the median one. The cardiac region convex, its summit is mounted with a large tubercle which is surrounded by about eleven tubercles. The intestinal region is mounted with about five tubercles, of which the median one is prominent and erect. The hepatic regions are armed with four or five tubercles; the branchial regions with large tubercles along the lateral margin, of which one posterior is prominent, corresponding to the usual lateral branchial spine; on the inner angle of this region, near the gastro-cardiac groove, is a group of four or five tubercles, and also three or four on either side of the cardiac region; along the postero-lateral border are also placed six or seven tubercles. On the pterygostomial region is a row of two erect tubercles, followed by another tubercle which is situated just above the base of the cheliped. Antero-external angle of the buccal cavern forms a lobular tooth.
The pseudorostral spines are subcylindrical and well divergent, the tips being very acuminate. The anterior angle of the supraocular eaves forms a sharp tooth. The postocular cups are almost lateral in position, their inner border is sinuate. The basal segment of antenna is distally armed with a slender spine, which is followed by a very broad tooth. The infraorbital tooth is small and tuberculiform.
Chelipeds (female) are not stouter than the ambulatory legs, the arm is mounted with three tubercles along the upper border, the fingers are compressed and short, somewhat concave on the inner surface. The ambulatory legs are thickly covered with tomentum, interspersed with bundles of long setae. (Sakai, 1938)
Type locality: Shimoda, Japan.
Range: Japan - Shimoda and Gobo (Sakai, 1938a), Shimoda, Kii Nagashima, Kii Minabe and Gobo, Wakayama Prefecture (Sakai, 1976a), Mage-jima, Kagoshima Prefecture (Takeda, 1977b), Ogasawara-shoto (Takeda & Kurata, 1976b), Kushimoto (Miyake, 1983); Philippines - north of Lubang Island (Serène & Vadon, 1981); 10-15 m.