(Sakai, 1937)
Carapace 1.4 times broader than long, regions not well-defined; dorsal surface covered with small granules; groove parallel to carapace border indistinct, resulting in narrow rim along margin of carapace, rim along antero- and postero-lateral borders with , posterior to sub-hepatic angle; branchiostegite with distinct patch of mushroom-like scattered shallow granule-lined circular depressions; shallow longitudinal groove lined with granules on region posterior to orbit, groove extends posteriorly to one quarter length of carapace; dorsal surface of antero-lateral border with longitudinal groove halfway down from front; distinct, narrow median longitudinal ridge running posteriorly to one-third carapace length; two short, oblique row of granules immediately behind posterior end of ridge, anterior to branchial humps; two, shallow rounded depressions on either side of anterior end of cardiac region; branchial regions raised and covered with irregularly shaped granulated ridges which enclose small circular depressions; shallow, irregularly shaped, granule-lined groove on either side of cardiac and intestinal regions. Front moderately bilobed, with circular depression immediately after median cleft; margin of sub-hepatic region protruded to produce obtuse angle, with triangular depression anterior to it; shallow, granule-lined groove on ventral surfacegranules; postero-lateral border beside cardiac region quite straight.
Basal segment of antennule entirely occupies fossa when closed; basal segment of antennae linked to antennulary fossa by means of short groove. Third maxillipeds densely covered with granules; merus with pointed apex, outer edge slightly convex, centre with round circular depression; ischium 1.9 times longer than merus along inner margin, inner border of outer surface with shallow granule-lined groove along three-quarters of inner edge.
Outer surface of chelipeds more granular than inner surface; fingers as long as palm; immovable finger with two parallel transverse rows of small granules on outer surface forming shallow groove in between, inner row reaching halfway to tip from proximal end, outer row reaching tip from proximal end, inner surface concave along inner edge; inner surface of movable finger with single transverse row of granules a slight distance from cutting edge; cutting edges of both fingers sparsely lined by denticulate teeth; distal end of inner surface of palm with scattered granule-lined depressions, inner edge with scattered large granules; inner edge of carpus and all edges of merus lined by scattered large granules. Outer surface of last pair of legs coarsely granulated, inner surface with flatter granules; proximal three-quarters of anterior edge and entire posterior edge of merus lined with row of large granules; posterior half of outer surface of propodus with clump of large granules; dactylus narrow and long, covered with small granules. Abdomen granulated, with two parallel, interrupted longitudinal grooves on either side of median line; sutures indistinct; terminal segment with very pointed apex. (Tan & Ng, 1995)
Type locality: Nagasaki, Japan.
Range: Japan - Nagasaki (Sakai, 1937a), Amakusa and Sea of Ariake (Miyake et al., 1962), coast of Fukuoka, Nagasaki, and Amakusa (Sakai, 1976a); Andamans, Bay of Bengal (Alcock, 1896).