Sakai, 1961
The carapace is almost circular in outline, the length being subequal to the breadth. The dorsal surface is moderately convex, uniformly covered with studded granules of different sizes. There is no distinct groove on the dorsal surface, besides that on either side of the intestinal region. The edge of the front is divided into two lobules by a wide but shallow median sinus. There is one tubercle on the subhepatic region, which can be seen in dorsal aspect. There are three tubercles on each lateral border, the middle one of which is smaller than the others. The posterior border is marked with two prominent tubercles, one on either side, and finally there is one tubercle on the intestinal region near the posterior border. Sometimes there is a small or vestigial tubercle on the postero-lateral border near the posterior tubercle.
The external maxilliped has the ischium and merus granulated, but the surface near the inner edge is non-granulated; its exognath is also granulated, the granules in the median line being of good size.
The male abdomen is composed of four parts, the formula being 1 + 2 + R + T; there is a prominent process near the end of the R-segment. The anterior pleopod of the male is very slender, its apex bent almost at right angles to the long axis.
The chelipeds of the full-grown male are about twice as long as the carapace; the merus and carpus are subcylindrical, and are uniformly covered with small studded granules; the propodus is somewhat compressed and is covered with studded granules which are visible under a lens. The fingers are a little shorter than the palm, the prehensile edges are thin and only indistinctly denticulate, leaving no hiatus between the two when closed.
The ambulatory legs are very slender, the merus, carpus and propodus are only indistinctly granulated along the anterior and posterior borders; the dactylus is thickly fringed with hairs along the superior border. (Sakai, 1961)
Type locality: Amadaiba, off the coast of Hayama, Sagami Bay, Japan, 70 m.
Range: Japan - Sagami Bay (Sakai, 1961, 1965, 1976), Mikawa Bay (Sakai, 1976a), Tosa Bay (Sakai, 1961, 1976); South China Sea; Philippines - north and west Lubang Island (Serène & Vadon, 1981), north of Lubang, north-west of Lubang, south of Manila Bay, west of Semirara Islands and north of Panay (Chen H., 1989); 35-300 m.