Takeda, 1972
Diagnosis: Carapace rather rectangular and almost flat laterally and posteriorly; dorsal surface smooth for its greater part and bears a fur along frontal, supraorbital and antero-lateral borders. Antero-lateral border with a ridge confluent with external orbital angle and with two lobular and a rudimentary teeth. Chelipeds heavy and distinctly unequal in both sexes. Ambulatory legs very slender. Merus and carpus with sparse hairs, and propodus and dactylus with dense fringes of hairs of various length. Dactyli of first three pairs subcylindrical, while in last pair dactylus rather depressed and weakly curved upwards near its tip.
Description of holotype: The carapace is rather rectangular and weakly declivous anteriorly, being almost flat laterally and posteriorly; the dorsal surface is for its greater part smooth and glabrous without distinct indication of regions; however, the gastro-cardiac transverse depression is faintly demarcated and marked with a pair of blotches; along the frontal, supraorbital and antero-lateral borders is a fur, and row of longish brush-like hairs runs transversely behind the front; the antero-lateral surface where is covered with a fur is also rendered distinct by the shallow depression and scantly provided with small rounded granules.
The antero-lateral border of the carapace is cut into three distinct lobular teeth, behind of which the fourth tooth is obscurely demarcated; they are crested and light-coloured, being more or less roughened by minute granules; the first is a mere ridge and confluent with the external orbital angle, stretching obliquely backwards; the second is the most prominent of series and bears its tip at the anterior end, its outer border being weakly convex; the third is rather similar to, but less prominent than, the preceeding. The postero-lateral border is weakly convergent and longer than the antero-lateral; its dorsal surface is rather sunken and provided with small granules; its posterior end is prolonged downwards. The posterior border of the carapace is wide, rimmed along the whole length and weakly concave in the middle.
The frontal breadth is about one third the breadth of the carapace, and the fronto-orbital breadth is about twice the frontal breadth and equal to the length of the carapace. The front is so declivous that its free margin is not visible in the dorsal view; it is cut into two truncated lobes by a median, small but distinct notch; each of the lateral angles is rounded and entirely continued to the supraorbital border; The supraorbital border is weakly raised and almost entire, but in reality, near the middle an indistinct notch is possibly traceable; the external orbital angle is slightly angulated and confluent with the first lobe of the antero-lateral border. The infraorbital border is nearly entire and more or less sinuate, its inner angle is rounded and ventrally convex. The eyestalk is swollen and covered with a fur on the upper surface, the cornea being very prominent; they are protruded from the general contour of the carapace. The antennal basal segment is short and not reached the short prolongation of the front, but its outer angle is raised higher than the inner infraorbital angle; the antennal flagellum is fine and slender, exceeding twice the length of the major diametre of the orbit.
The third maxillipeds are broad. The ischium is glabrous and bears a median rather oblique groove; the inner margin of the ischium is sharp only with sparse hairs, and its anterior angle is weakly extended forwards and rounded. The merus is subquadrate and its median surface is weakly raised on account of presence of two depressions along the inner margin and the anterior and outer margins; the antero-external angle of the merus is thin and weakly curved ventrally, being only slightly angulated.
The chelipeds are heavy, and not quite but distinctly unequal, the left being larger. The merus is very small and only the distal part is exerted beyond the carapace; its whole inner surface is excavated, and the proximal half of the upper border is crested. The carpus is large and glabrous only with the fringes of short hairs on the distal inner and outer margins; the inner angle is produced into a lobular tooth that is weakly curved upwards and not angulated. The palm is entirely smooth and naked. In both chelae the fingers are rather stout, leaving a rarrow gape along the whole length; the cutting edges of both fingers are irregular and blunt with the molar-like teeth in the larger chela and sharply toothed in the smaller chela; the tips are also obtuse in the larger chela and markedly sharp in the smaller. The colouration is restricted to the distal halves of the immovable fingers and to the distal two thirds of the movable fingers in both chelae.
The ambulatory legs are very slender; the third pair is much longer than the others, the second is the next and the first and the fourth are subequal. The anterior border of the merus is thin and minutely serrulated. The merus and carpus are sparsely provided with hairs, while the propodus and dactylus are densely fringed with long hairs of various length. The dactylus is only slightly shorter than the propodus; in the first three pairs each of the dactyli is subcylindrical, while in the last pair it is rather depressed and weakly curved upwards near the tip. (Takeda, 1972c)
Type locality: S. W. Madali, Goror Island, Palau, 7°20'30"N, 134°28'E.
Range: Japan - Oshima Passage, Amami-Oshima (Takeda, 1989); Palau (Takeda, 1972c, Takeda & Shimazaki, 1974); 30 m.