(Alcock, 1898)
The carapace is very broad and strongly convex fore and aft; the surface is entirely smooth and ivory-like without any indication of the regions. The front is nearly perpendicularly deflexed so as to conceal the true border, and bears a small but V-shaped median sinus; the frontal lateral angle is somewhat angular, but not prominent, and is separated by a shallow indistinct depression from the supraorbital angle which is also not prominent. The orbit is somewhat ventral; its supraorbital border is weakly sinuate and minutely granulated laterally, but is entire; the external angle is not produced at all, and the infraorbital border is also minutely granulated and rounded near and at its inner angle. The antennule is folded obliquely; its peduncle is short and stout; a curved crest is present at the lower border of the fossa. The basal antennal segment, which is truly the second, is short and not quite reached the front; its outer angle is slightly produced and protruded obliquely-forward; the second and third segments are subequal in length, but the former is stouter, the second is hardly reached the short ventral prolongation of the front, and the third is raised just to the supraorbital angle; the antennal flagellum is fine and slightly longer than the major diametre of the orbit.
The antero-lateral and postero-lateral borders are not distinctly delimited. The antero-lateral portion is arched and bordered with a thick blunt crest; otherwise it bears two very indistinct depressions, so that it is composed of three low lobes. The postero-lateral portion is strongly convergent and concave dorsally.
The chelipeds are heavy and unequal in both sexes. The merus is short, and its upper border is strongly crested; the crest bears minute interruptions along the whole length, and a subterminal larger one. In the smaller specimen the outer surface of the larger carpus is entirely smooth, while that of the smaller carpus is thickly covered with small conical granules, of which those near the distal end are more prominent; in the larger specimens the smaller carpus is entirely smooth like the larger one; the inner angle of each carpus is produced in a blunt tooth which is not conical, but ridge-like, and is provided with some indistinct granules. In the larger specimens the larger palm is entirely smooth, glabrous and devoid of hairs, while the smaller palm is thickly covered with conical granules interspaced with rather sparse short hairs; those granules are so thick and somewhat squamiform that they are not arranged in longitudinal rows; in the smaller specimen the larger palm is also entirely covered with granules which are less prominent than those on the smaller palm, and the hairs are very sparse. In both chelae the fingers are stout and high; they are somewhat similar in both chelae, but in the smaller chela the proximal halves of the fingers are occupied with granules, the longitudinal furrows are much prominent and the teeth are sharper.
The ambulatory legs are comparatively slender. The merus is armed with a row of minute granules on the upper and lower borders respectively, and provided with very sparse short hairs. The carpus and propodus are armed with many conical granules of good size on and near the upper borders and provided with long silky hairs mostly on the upper borders; in the last pair those segments are covered with minute granules on the upper surfaces. The dactylus is armed with several spinules on the upper border, and covered with dense silky hairs. The male abdomen is narrow, and the first male pleopod is similar to those of the members of the genus Pilumnus. (Takeda & Miyake, 1968c)
Type locality: off south-east corner of Sri Lanka, 58 m.
Range: Maldives - Mulaku Atoll (Borradaile, 1902b, Galil & Takeda, 1988); Sri Lanka (Alcock, 1898); Japan - Ogasawara-shoto (Odhner, 1925), Shiono-misaki and Kii Minabe (Galil & Takeda, 1988); East China Sea (Takeda & Miyake, 1968c, 1969, 1972, Galil & Takeda, 1988); Philippines - Palanog Lt., east of Masbate Island (Garth & Kim, 1983, Galil & Takeda, 1988).