Takeda & Miyake, 1969
Small species. Carapace convex anteriorly, bearing no regional indication except for median gastric indication; surface smooth, shining, sparingly provided with stiff hairs of various length; front declivous, cut into two truncated lobes by a median small sinus, being followed with a transverse row of hairs. Eyestalk very swollen, provided with some hairs near cornea; supraorbital border entire, slightly raised, thin. Antero-lateral border with two small spine-tipped teeth in addition to external orbital angle; behind them a vestigial third tooth capped with a minute spiniform granule. Postero-lateral border nearly straight, only slightly convergent. Chelipeds unequal; merus armed with a prominent subterminal and a small terminal spine on its upper border, with two spines on inner lower border; outer surface of carpus with dense minute granules and hairs of various lengths; carpus with a spine-tipped tooth at inner angle; palm of larger chela covered with small granules and hairs on its outer upper half; granules beaded to some longitudinal series; outer lower and sital surfaces devoid of hairs and granules; smaller palm with dense hairs of various lengths and with spiniform granules on entire surface; cutting edges toothed deeply in larger chela, much shallowly but sharply in smaller chela. Ambulatory legs very slender and bordered with stiff hairs of various length; each merus of first three pairs armed with a curved spinule on its upper border. (Takeda, 1998)
Diagnosis: Small species. Carapace ill-defined, smooth and sparingly provided with stiff hairs anteriorly. Antero-lateral border with two small spine-tipped teeth and a vestigial third one. Ambulatory legs slender. Each merus of first three pairs with a spine on upper border.
Description of holotype: The carapace is convex anteriorly and bears almost no regional indication except for the usual median gastric indication; the surface is very smooth and shining, and mainly on the anterior one-third sparingly provided with microscopical pits from which single stiff hairs of various length arise; the hairs behind the front are arranged to form a transverse row. The front is declivous and cut into two lobes by a median small sinus; each frontal lobe is nearly truncated and bears no lateral lobule; through the shallow dorsal depression it is continuous with the supraorbital angle which is also not produced. The eyestalk is very swollen and provided with some hairs near the cornea. The supraorbital border is entire, slightly raised and thin. The infraorbital border bears a deep interruption near the external orbital angle and is setose near the inner angle which is not produced and touched with the middle portion of the basal antennal segment; the inner angle of the basal antennal segment is just touched with the ventral prolongation of the front; the antennal flagellum is slender, about twice as long as the major diametre of the orbit, and provided with microscopical short secondary hairs. The endostomial ridge is strongly developed.
The antero-lateral border is armed with two small spine-tipped teeth in addition to the external orbital angle; those two teeth are subequal and directed forwards; behind them there is a vestigial third tooth that is capped with a minute spiniform granule. The subhepatic region is granulated, and one of the granules near the deep notch just below the external orbital angle is fairly large and visible from above. The postero-lateral border is nearly straight and only slightly convergent.
The chelipeds are unequal, the right one being the larger. The merus is armed with a prominent subterminal and a small terminal spine on the upper border, and with two spines on the inner lower border. The outer surface of the carpus is rather densely covered with minute granules and hairs of various length, those hairs arising mainly around the granules; the inner angle of the carpus is produced in a spine-tipped tooth. The palm of the larger chela is covered with small granules and hairs on the outer upper half; those granules are beaded to some longitudinal series, around which the hairs arise; the outer lower and distal surfaces are devoid of hairs and granules; the smaller palm is provided with dense hairs of various length and with spiniform granules on the entire surface; the hairs mostly arise around the granules which are beaded to about six longitudinal rows. The cutting edges are toothed deeply in the larger chela, and much shallowly but sharply in the smaller chela.
The ambulatory legs are very slender and bordered with stiff hairs of various length. Each merus of the first three pairs is armed with a curved spinule on the upper border, which is nearly transparent and readily overlooked; otherwise the upper border of each merus is roughened at the bases of hairs, and bears a rather prominent, subterminal interruption. (Takeda & Miyake, 1969c)
Type locality: Kasari-zaki, Amami-Oshima, Japan.
Range: Japan - Amami-Oshima and Tokuno-shima (Takeda & Miyake, 1969c).