de Haan, 1835
Carapace transversely oval, smooth, convex and punctulate; on its surface symmetrically disposed red blots; regions ill defined, only a distinct H-shaped depression located between gastric and cardiac regions. Antero-lateral margin smooth and unarmed. Posterior margin slightly concave. Front broad, divided into 2 lobes, anterior margin of lobe slightly concave near the outer-distal angle. Orbit small, eye-peduncle stout and short.
Chelipeds smooth, symmetrical. Merus with several obtuse teeth on dorsal margin. Carpus with inner- and outer-distal angle blunt and produced. Palm subequal to finger in length. Fingers bearing irregular obtuse teeth on the inner margins. Ambulatory legs elongate, thin and cylindrical; surface smooth and glossy, first leg the longest, the second to fourth pairs gradually decreasing in length; dactyli sharp, provided with short hairs.
First pleopod of the male elongate and slender, distal part armed with long hairs on the inner side, and acute granules on the outer side. Male abdomen triangular; third to fifth segments fused, but suture still recognizable; the terminal segment with distal margin bluntly round. Female abdomen oblong. Carapace length of the male 22.5-27.5 mm, breadth 30-37 mm; of the female, length 25.1 mm, breadth 34.5 mm. (Dai & Yang, 1991)
Type locality: Japan.
Range: Persian Gulf - Kharg (Stephensen, 1945); Myanmar - Irrawaddy Delta (Alcock, 1898); Japan - Sagami Bay, Gobo, Wakayama, Nanki Shirahama, Tosa Bay and Nagasaki (Sakai, 1939), Sagami Bay (Sakai, 1965b), Sagami Bay, Manazuru, Kii Nagashima, Wagu, Kii Minabe, Tosa Bay, and Nagasaki (Sakai, 1976a), Tanabe (Miyake, 1983); Taiwan - Hsiak'unhsen and Tingch'ieting (Lin, 1949); China - (Parisi, 1916), Hong Kong (Alcock, 1898), Shaotsun and Fuzhou, Fujian Province (Shen, 1940b), Hainan Island and Fujian (Dai & Yang, 1991); Vietnam (Guinot, 1971b); Philippines - Manila Bay and north of Lubang Island (Serène & Vadon, 1981); Australia - Cape Gloucester (Rathbun, 1923a), Moreton Bay (Campbell & Stephenson, 1970).