(Takeda & Nagai, 1986)
Carapace subpentagonal in its outline, with a deep cavity at each antero-lateral part characteristic for the genus; dorsal surface uneven and rather flattened as a whole, being thickly covered with numerous small pits to form a reticulation; in reality, the reticulation consists of beads of minute pearly granules, that are visible only on high magnification and worn out to be smooth for most parts of gastric region; dorsal surface divided into regions and armed with eight tubercles arranged symmetrically, i.e., one on each supraorbital region, one on each protogastric subregion, and two on each branchial region; tubercles surmounted with clustered minute granules; supraorbital region thickened and separated from protogastric subregion by a wide depression; protogastric subregion occupied by a tubercle for its median part, being separated from anterior extension of mesogastric subregion by a small line which is not grooved; gastric region as a whole separated from branchial and cardiac regions by a wide and deep depression; cardiac region transversely elliptical and convex for and aft, being indistinctly delimited at each side from branchial region, but completely confluent posteriorly with flattened intestinal region; branchial region occupied by two tubercles for its most part.
Front developed so as to be rather triangular as a whole; in the holotype the right lobe is broken, so that the details of median indentation are obscure. Orbit small and completely occupied by stout eyestalk and cornea; eyestalk with several pearly granules along distal margin; inner part of supraorbital margin longitudinal or only slightly oblique, and almost entire except for possible trace of a closed fissure; external orbital angle not developed, being directly continuous with antero-lateral margin of carapace. Main part of antero-lateral margin of carapace deeply excavated to form a cavity; upper margin of the cavity is thick, but its anterior and lower margins thin and crested; its lower margin fringed with several granules, one or two of which are developed as outgrowths into the cavity; bottom of the cavity is eroded and provided with some granules. Postero-lateral margin of carapace behind the cavity is continuous with lower margin of the cavity, fairly strongly convergent posteriorly and fringed with a line of pearly granules, its anterior end being distinctly angulated in dorsal view; the line of pearly granules curved inward at the middle of margin of carapace behind the cavity, and then changes its direction to lateral end of posterior margin of carapace; thus, a small, rather concave facet is formed at each postero-lateral part of carapace, and the fourth ambulatory legs are folded onto them.
Antennule folded obliquely under each frontal lobe. Antennal basal segment wide and oblique, its antero-inner angle truncated and widely touched with well developed prolongation of supraorbital margin; antennal flagellum feeble, arising from inner half of distal margin of basal segment. Third maxilliped thickly covered with truncated pearly granules and scattered setae; ischium oblong, its inner margin being fringed with prominent granules and short setae; merus about two-thirds as long as ischium with its distal margin oblique; exopod also granulated and rapidly narrowed distally, reaching just to antero-outer angle of merus.
In the holotype male the chelipeds are slightly unequal, the right being the larger, although the formation is almost identical with each other. Merus short and almost disguised under carapace; upper margin thin and beaded with conical granules of variable sizes, and outer subdistal part with a granulated ridge along distal margin. Carpus large, and its outer surface very uneven with minute pits, irregular reticulation and grooves; distal part of outer surface thickened; distal half of inner margin obliquely cut off, its surface being smoothly continuous with outer surface, and its distal margin being granulated. Outer surface of palm also uneven and thickly covered with minute granules, with about three rows of larger granules; upper margin of palm strongly crested and rather directed inward, its inner half being excavated together with proximal upper part of inner surface of palm; inner surface of palm granulated much sparsely than outer surface, but granules near the excavation are larger. Fingers granulated on outer surfaces, pointed at tips, and meet throughout the whole lengths of fingers; some blunt teeth on cutting edges.
In the holotype the first two ambulatory legs are missing. Last two pairs comparatively short and thickly covered with pearly truncated granules on upper surfaces; granules variable in size, but those on posterior margins of merus and propodus are apparently larger; anterior margins of carpus and propodus fringed with several and some conical granules, respectively.
Thoracic sternum and abdomen thickly covered with truncated granules, being more or less eroded. Male abdomen with five pieces; third to fifth segments fused into one piece, with indication of vestigial segments by interruption of granules and lateral indentations. Male first pleopod with six long hairs at inner subterminal part behind short beak; subterminal outer surface thickly covered with conical teeth directed toward base. (Takeda & Nagai, 1986)
Type locality: Koza, north-east of Kushimoto, Kii Peninsula, 40-50 m.
Range: Japan - Koza, Kii Peninsula (Takeda & Nagai, 1986); 40-50 m.