(Sakai, 1965)
The carapace is transversely suboval, with the dorsal surface sloping down in the anterior one third and rather flat in the posterior two thirds. The areolae are well defined and covered with granules, of which those on the gastric, hepatic and branchial areolae are mostly arranged in transverse or oblique rows of various lengths; the remaining areolae are dotted with tiny granules. The protogastric areolae are divided into two areolets, the inner one of which is continuous with the well defined epigastric areolet, while the outer one is again obscurely subdivided; the hepatic areolae are also anteriorly subdivided.
The front is half as wide as the carapace, divided into two lobes by a rather deep median sinus; each lobe is double-edged, the upper edge being granulate and the lower one sinuate with its inner angle markedly lobulate and its outer angle also lobulate and deeply separated from the preorbital angle. The upper orbital border has two fissures, the outer orbital tooth is low and rather obscure, and the lower orbital border is armed with two suborbital teeth, which can be seen from the dorsal side.
The antero-lateral borders are continuous with the antero-external angle of the buccal frame and armed with four prominent teeth, of which the posterior three are the tip, while the anterior one is rather small and located on the subhepatic area. Behind the outer orbital tooth, the true antero-lateral border is represented by a granulated ridge leading to the second antero-lateral tooth. The postero-lateral borders are just as long as the antero-lateral, the surface inside of these borders is covered with studded granules. The posterior border is straight, slightly broader than the fronto-orbital width.
The chelipeds are asymmetrical, the right one being the heavier. The merus is rather thin; the carpus is massive and covered with tubercles of various sizes, its upper surface sulcate and its inner angle armed with an upper and a lower process; the propodus is also tuberculate and sulcate and there are four or five large tubercles on the upper inner edge. The black colour of the fingers does not extend onto the propodus.
The ambulatory legs are covered with tiny granules; the anterior border of the merus is armed with a series of tubercles of various sizes, the carpus is medially sulcate, and its anterior border marked with three or four tubercles, the terminal one of which is the largest. The propodus is not armed. (Sakai, 1965)
Type locality: west of Jogashima, Sagami Bay, Japan, 80 m.
Range: Japan - west of Muroto-misaki (Yokoya, 1933), Sagami Bay, Kii Nagashima and Tosa Bay (Sakai, 1965a, b), Sagami Bay, Kii Nagashima, Kii Minabe, and Tosa Bay (Sakai, 1976a); China Sea (Guinot, 1968a); 15-80 m.