Yokoya, 1933
The species is distinctly different from other species of this genus in the smooth margin of the carapace, which is slightly carinated on the antero-lateral margin. The lateral margins are a little converged posteriorly. The surface is smooth and covered with short hairs. The front is about one third as wide as the carapace. Along the frontal and the antero-lateral margins there are rather long hairs.
The abdomen in male consists of seven segments, in which the first is the widest of all and occupies the whole space between the bases of the last pair of legs. The second segment is much narrower, while the third is wide, but does not occupy the whole width of the sternum.
The first antenna is transversely plicated. In the second antenna the basal joint scarcely reaches the front, the flagellum is rather long. The buccal area is broad anteriorly; the merus of the third maxilliped is dilated at the antero-external corner. The chelipeds are subequal, smoothly surfaced and covered with short hairs, while the carpus and the palm are provided with more or less longer hairs on the upper margins. The succeeding pairs of legs are similar in feature and the penultimate pair is the longest. The dactylus of the last is somewhat reversely curved. (Yokoya, 1933)
Type locality: south of Satsuma, Kagoshima Prefecture, Japan, 192 m.
Range: Japan - Kagoshima (Yokoya, 1933).