Stimpson, 1858
Morphologically this species is characterized by the following.
1. The species is usually of small size, its biological minimum is about 20 mm in carapace breadth.
2. The carapace and the cheliped bear tubercles and short striae. The propodus of the 2nd ambulatory leg is 2.0 times as long as broad; the dactylus is stout.
3. The merus of the third maxilliped is 1.7 times as long as broad.
4. The penultimate segment of the first pleopod is straight. The ultimate segment is slightly curved outwards, and both the lateral sides is straight near the tip. The synovial membrane is 3.0 times as long as broad. (Minei, 1973)
Type locality: Amami-Oshima, Japan.
Range: Japan - Amami-Oshima (Stimpson, 1858b, 1907, A. Milne Edwards, 1869, de Man, 1892b, Ortmann, 1897b, Minei, 1973), Okinawa (Parisi, 1916), Tokuno-shima (Minei, 1973), Amami-Oshima and Tokuno-shima (Sakai, 1976a).