Ng & Nakasone, 1993
Description of male: Carapace slightly longer than broad; dorsal surface smooth, glabrous, without setae; regions not defined, strongly convex transversely and longitudinally, gastric region most convex. Frontal margin slightly convex, entire; lateral lobes not visible dorsally, slightly deflexed downwards; lateral edges apparently confluent with supraorbital margin from dorsal view, but not confluent from frontal view; inner edges of smooth, entire supraorbital margins strongly deflexed downwards, much more than outer edges of front, forming slight crimp at junction between frontal and supraorbital margins. Infraorbital margin not distinctly cristate, slightly raised; not granulated or striated. Antero-lateral margin slightly arcuate, subcristate, very faintly trilobed, lobes separated by very broad, shallow clefts; external orbital lobe most distinct, very broad; second, third lobes more like weak undulations. Postero-lateral margins not sharply demarcated from antero-lateral margin, appearing almost straight, distinctly converging. Orbits small, eyes completely filling orbit, corneae well developed. Pterygostomial, suborbital, branchial regions smooth. Orbital hiatus completely filled by large basal antennal segment; flagellum completely enclosed within orbit. Antennules folding obliquely, fossae very large; basal segment large, subtriangular in shape, broader than long. Posterior margin of epistome weakly sinuous, with 3 distinct ridges (1 median, 2 lateral); ridges separated from each other by narrow gap. Endostomial region with 3 well developed longitudinal palatal ridges (1 median, 2 lateral); lateral palatal ridges joining inner edges of lateral ridges of posterior epistomial margin.
Third maxilliped with foliaceous merus, broader than long; antero-lateral angle strongly produced, auriculiform; distal margin distinctly bilobed, outer lobe larger, its base with small median cleft. Ischium longer than broad, sulcus not discernible. Small, distinct rhomboidal gape formed between inner margins of meri and ischia of third maxillipeds then closed. Exopod with obtuse, blunt inner subdistal angle, flagellum longer than width of merus.
Chelipeds small, subequal, outer, inner surfaces smooth, glabrous; merus, carpus without spines or teeth; inner distal angle of carpus with broad, low, rounded lobe. Outer surface of chela with low but distinct ventral ridge running from near proximal part of palm to almost tip of pollex; inner surface without setae at base of fingers. Fingers distinctly longer than palm; cutting edge of both fingers with numerous denticles, ending in recurved, sharp tips; no gape discernible when fingers closed.
Ambulatory legs with second pair longest. All segments smooth, without spines or setae. Dorsal and ventral margins of merus sub-cristate, dorsal margin with blunt subdistal tooth. Dactylus tapering to slender, acute tip.
Male abdomen triangular; lateral margins sparsely setose; first abdominal segment weakly arched, with very weak transverse ridge; second segment narrow, short; third segment broad, slightly swollen laterally but medially depressed with proximal margin broader than distal margin, lateral margins rounded; fourth segment broader but shorter than fifth segment; fifth segment with proximal and distal margins straight, lateral margins slightly concave; sixth segment quadrate, lateral margins trapezoidal, weakly convex, proximal margin slightly concave, convex medially. Telson sub-triangular, lateral margins weakly concave, distal margin rounded.
Lateral margins of first 2 thoracic sternites finely granulated; suture between sternites 2 and 3 slightly convex towards abdomen; lateral margins of sternites 3 and 4 sinuous, with deep, broad notch demarcating edge of suture; median groove between sternites 5 and 6 narrow; space between sternites 8 very narrow throughout length.
Penis located at base of eighth sternite. G1 relatively slender, weakly curving outwards, reaching to anterior margin of fifth sternite; terminal lobe elongate, apparently 2-articulated, dorsally curved; genital opening lateral to base of terminal lobe; subterminal lobe chitinous, rounded, narrower than terminal lobe, densely setose. G2 short, small. (Ng & Komai, 2000)
Type locality: Kunri-Hama Beach, Sesoko-jima, Okinawa, Japan, under littoral coral sand.
Range: Japan - Okinawa (Ng & Nakasone, 1993), Ishigaki-jima (Ng & Komai, 2000).