(K. Sakai & Yatsuzuka, 1980)
Carapace punctate on its surface, and 1.2-1.3 times as broad as long; proto- and mesogastric regions noticeably concave; cardiac furrow and cervical groove present; lateral margins divergent posteriorly, tridentate behind external orbital tooth, posterior tooth scarcely developed; branchial region with three granulated lines. Suborbital ridge of male consisting of 11-12 protuberances, of which the innermost 1-2 ones a little elongate, striate vertically, and confluent; suborbital ridge of females consisting of 12-13 isomorphic granules. Chelipeds subequal, palm smooth, fingers gaping in proximal half, with teeth on cutting edges. Pleopod 1 elongate, terminal part curved dorsally, suture torded from ventromesial to dorsal surface at a small distance from tip; palp attached to stem. (Türkay 1995)
Type locality: estuary of Muromi-gawa, west side of Hakata Bay, Japan.
Range: Japan - Nagasaki and Amakusa (Sakai, 1939), Miura Peninsula, Shimabara, and Ishigaki-jima (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Fukuoka (Sakai K. & Yatsuzuka, 1980), Tsuboi-gawa, Kumamoto (Miyake, 1983); Korea - Koje-do (Sakai, 1939); China - Shandong Peninsula (Shen, 1932).