Sakai, 1963
The entire animal seems to be smooth, but under the magnifying glass the surface of the carapace and chelipeds is thickly covered with very fine granules. The carapace is apparently broader than long, the middle portion is markedly convex, while the postfrontal region is sunk, and the metagastric and cardiac areas are respectively marked with an obtuse protuberance. The front is divided into four teeth, of which the outer two are prominent and the inner two are small and dentiform, separated by a V-shaped median frontal sinus. The two upper orbital fissures are distinct. The hepatic border is moderately convex, its middle portion is obscurely marked with an obtuse tooth. The antero-lateral and postero-lateral borders are entirely continuous, thin and cristiform, the margins being somewhat upturned as in the case of the related genus Cryptocnemus.
The chelipeds are slender, twice as long as the carapace; the merus, carpus and propodus are subcylindrical, but the anterior and posterior borders are not at all cristiform. The fingers are as long as the propodus, clearly bent inward from the long axis of the propodus; their prehensile edges are uniformly cut into tiny sharp teeth.
The ambulatory legs are very slender, the merus, carpus and propodus are subcylindrical and the dactylus is slender and as long as the propodus.
The abdomen of the female is composed of three pieces, the terminal segment is very narrow and oblong, inserted into the deep sinus of the penultimate composite segment. (Sakai, 1963)
Type locality: Amadaiba, off Hayama, Sagami Bay, Japan, 70 m.
Range: Japan - Sagami Bay (Sakai, 1963, 1965, 1976), south off Tsushima (Takeda, 1973c); Philippines - east of Lubang Island (Chen H., 1989); 65-137 m.