(Borradaile, 1900)
The carapace is more or less transversely oval in its outline, being weakly convex anteriorly and nearly level from side to side; the dorsal surface is almost naked and smooth to the unaided eye, and well divided into areolae by shallow but distinct rather wide furrows; the areolae are, however, covered with thick microscopical granules, being not convex; the front is almost transverse or only slightly produced and convex near the median V-shaped sinus, and bordered with minute rounded granules; of the dorsal areolae, 1. 2 and 3M and an areola behind the external orbital angle (1, 2 and 3L) are prominent; 2M is incompletely subdivided anteriorly by a short, shallow longitudinal furrow; the posterior end of 1M is elongate, and in reality the separation from the inner part of 2M is indistinct; at the antero-inner angle of the outer part of 2M is a longish seta or hair; the anterior process of 3M is narrow and ends at the middle way of 1M.
The inner part of the supraorbital border is rather thick, its inner angle being rounded and deeply separated from the outer angle of the front; two supraorbital fissures are closed, but traceable by the shallow depressions; the true external orbital angle is not produced at all, just at which is a third closed fissure; beneath the fissure the external angle of the infraorbital border is produced and visible from above; the infraorbital border is weakly concave throughout the length, and its inner angle is thereby slightly raised, but not angulated. The antennal basal segment is rather wide but short; its inner angle is just touched with the short ventral prolongation of the front, and the outer angle is raised to the level of the inner infraorbital angle; the antennal flagellum is rather stout and only slightly longer than the major diametre of the orbit, being provided with microscopical secondary setae.
The antero-lateral border of the carapace is armed with four stout teeth behind the external orbital angle; the first tooth is only a rounded prominence, being separated indistinctly from the external orbital angle and by a shallow bight from the external angle of the infraorbital border just below the external orbital angle; the last three teeth are subequal, and obtuse at the tips but apparently sharper than the first tooth; they are somewhat directed obliquely upwards and separated from each other by a dorsal deep depression. The postero-lateral border is strongly convergent and directed downwards, so that its dorsal surface is deeply sunken. The true posterior border of the carapace is as wide as the front.
The chelipeds are heavy, unequal and unlike each other. In both specimens examined the right one is much larger than the other. In each cheliped the merus is short and stout; the upper border of the larger merus is strongly crested and distally armed with two or three rounded granules, while in the smaller cheliped the upper border of the merus is also crested and armed with two or three sharp spines, of which the distal one just behind the interruption is the longest. The carpi of both chelipeds are alike each other in spite of the different size; the outer surface is very rugose with depressions and granulated prominences; two transverse furrows along the distal margin and at the middle are rather deep, but the prominences are not strongly convex; otherwise, the minute granules on the prominences are not sharp, but almost worn out in their appearances. The palm of the larger chela is very swollen and extremely roughened by the blunt granules and granulated prominences of various size; at the surface near the lower border the granules become indistinct, diminishing the size; at the middle surface the larger granules are indistinctly beaded to form two or three longitudinal series. The palm of the smaller chela is slender and about half height of the larger palm, tapering only slightly; its outer surface is also roughened by conical large granules and minute ones, and provided with several longish, sparse hairs; at the middle surface the larger granules are beaded to form three or four rather distinct transverse series. The fingers of the larger chela are stout and about half the length of the larger palm; each of the cutting edges bears several blunt teeth, the tips of the fingers being blunt; at each of the inner surfaces are two tufts of hairs, of which the distal one on the immovable finger is the most prominent. The smaller fingers are slender and also about half the length of the smaller palm, being sharply toothed on the cutting edges; the inner surfaces are also provided with hairs which are not distinctly tufted.
The ambulatory legs are comparatively stout. The greater part of the merus is naked only with a fringe of hairs along the upper border; only in the merus of the last ambulatory leg the fringe of hairs is restricted to the distal part of the upper border; each of the upper borders is armed with a row of conical granules, which is not disguised by the fringe of hairs. The carpus, propodus and dactylus are densely covered with short felt-like hairs, in which several long hairs are implanted; in addition, the upper borders and surfaces of the carpus and propodus are armed with rather sparse conical granules, of which those on the upper surface of the carpus are distinctly beaded to form a longitudinal row; the dactylus is much narrower than the propodus, and armed also with several sharp, more or less elongate granules on the upper surface and with thick yellow, semitransparent spinules on the upper border near the terminal claw.
In life the carapace is dark purple with white interregional furrows and also with white moiré blotches. The chelipeds are of the same colour as the carapace with some prominent white spots on the outer surface of the palm; the fingers are black with white tips and teeth. The ambulatory legs are much light-coloured. (Takeda & Miyake, 1969f: 196)
Type locality: Rotuma Island.
Range: Japan - Yoron-jima (Takeda & Miyake, 1969f); Rotuma Island (Borradaile, 1900, Guinot, 1968a).