Sakai, 1938
The carapace is broadly triangular and its upper surface somewhat depressed; the regions being distinctly divided by deepish grooves. The gastric region has four tubercles, of which the two median are in a transverse line between the anterior and posterior ones. The cardiac region conical and mounted with a tubercle, intestinal tubercle also distinct. The hepatic spine slender and curved forwards at tip; the lateral branchial spine very prominent, projecting backwards, upwards and forwards at tip; two tubercles on epibranchial region and also another on the inner side of the lateral spine.
The pseudorostral spines are divergent at an angle of about 50°; their bases flattened and their tips acuminate and curved outwards. Preocular spine very acuminate, the posterior angle of the supraocular eave marked by a rounded angle; the postocular tooth as strong as the hepatic spine. Four tubercles on the pterygostomial ridge and a row of three or four tubercles above the epimeral ridge.
Chelipeds are stout; ischium with two lobular teeth on the anterior border, arm with four crested longitudinal ridges, each ridge being armed with three or four irregular teeth; wrist with its outer and inner edges sharply crested and with two spine-like tubercles on the upper border.
Ambulatory legs are covered with velvet-like tomentum and also fringed with club-shaped hairs on anterior and posterior edges. A series of curled hairs on either side of the gastric region at the base of the rostral spine and on the lateral surface of the branchial regions, otherwise the carapace is naked. (Sakai, 1938)
Type locality: Shimoda, Japan.
Range: Japan - Shimoda, Ise Bay, Gobo and Wakayama (Sakai, 1938a), Sagami Bay (Sakai, 1965b), Sagami Bay, Izu Peninsula, Mikawa Bay, Shima Peninsula, and Kii Peninsula (Sakai, 1976a), Yamagata Prefecture (Suzuki S., 1979), south of Goto-retto (Griffin & Tranter, 1986a), Shimoda, Mikawa Isshiki, Wagu, Kii Minabe and Tosa Bay (Muraoka, 1998); China - Jiaozhou Bay (Shen, 1937); Taiwan Strait (Griffin & Tranter, 1986a); up to 72 m.