Sakai, 1938
The carapace oblong, the regions faintly defined and indistinctly tuberculated. There is no spine on the dorsal surface of the carapace besides a small lateral spinule on either branchial region. The pseudorostral horns are deflexed and projecting from a lower level; they are almost continuous but leave a narrow median interspace near the base, their tips being divergent. The supraocular eave laterally dilated and the preocular spine well defined, the postocular cup also produced into a spine at tip but the upper orbital sinus entirely closed.
The basal segment of antenna very broad and laterally expanded, the antero-external angle being produced into a spine. The infraorbital lobe is rudimentary and is placed at the outer side of the green gland. The pterygostomial ridge has a curved row of two or three tubercles. The merus of the external maxillipeds is much broader than the ischium, and its antero-external angle extremely produced.
Chelipeds of the female not stouter than the ambulatory legs, each segment being unarmed and covered with short hairs; the fingers are about half the length of the palm and do not gape.
The ambulatory legs are also unarmed and covered with hairs, the first pair is very slightly longer than the other pairs, which are not much unequal in length.
Abdomen of female distinctly seven-segmented. (Sakai, 1938)
Type locality: coast of Wakayama, Japan.
Range: Japan - coast of Wakayama (Sakai, 1938a), coast of Wakayama and Tosa Bay (Sakai, 1976a).