Takeda, 1989
Description of holotype: Carapace wider than long, hexagonal rather than quadrate, fairly convex in longitudinal direction; dorsal surface divided into regions by linear, wide and smooth furrows; regions covered with minute granules, most of which are uniformly dispersed and neither sharp nor rounded; frontal region large, divided into two by a median longitudinal furrow; epigastric region small, but distinct, with a short transverse row of granules along its anterior margin, being fairly distinctly isolated from frontal region by a transverse furrow and very indistinctly from inner part of protogastric region; anterior part of protogastric region imperfectly divided into two for a short way by a longitudinal furrow from outside of epigastric region; anterior part of mesogastric region narrow, extending just to a level of median part of epigastric region; cardiac region large, flattened, with microscopical granules; epibranchial region with two prominences which are composed of several granules, viz., one outside of protogastric region and the other inside of antero-lateral border between first and second teeth; a transverse region between second antero-lateral tooth and posterior part of mesogastric region; its posterior furrow delimiting this region from posterior branchial region transverse for its most part, directed forward at its lateral part, and then directed laterally toward posterior end of second antero-lateral tooth; posterior branchial region divided into two by an oblique linear furrow.
Frontal margin concave for its median 1/3, with a median small notch in dorsal view; in frontal view each part of frontal margin produced medially as a convex lobe and directed perpendicularly downward; lateral end of frontal margin produced as triangular lobe which is separated shallowly from median lobe by a wide depression and deeply from inner angle of supraorbital margin. Orbit 1/2 as wide as frontal margin; supraorbital margin transverse for its most part, with traces of two interruptions, granulated throughout its length, narrowly raised for its outer half; external orbital angle not produced.
Antero-lateral margin weakly convex, with a short ridge of several granules and following two more or less tuberculated teeth, the first of which is more strongly directed forward; postero-lateral margin straight, convergent, with a small conical tooth at its anterior end just behind a furrow following second antero-lateral tooth.
Antennule folded horizontally. Basal segment of antenna just touched with ventral prolongation of front. Third maxilliped wide, smooth, bare; outer surface of ischium with a longitudinal linear groove, and inner margin cut into more than ten blunt teeth fringed with sparse short setae.
Chelipeds supequal, covered with conical granules of variable size so as to be scaly in appearance; merus short, protruded beyond carapace only for its distal part, being armed with some sharp granules on its upper margin; carpus rough with solitary and aggregated granules and a median longitudinal and a distal submarginal grooves; inner angle of carpus armed with a main upper and a subsidiary lower tubercles; palm with a longitudinal groove on its outer upper surface; upper margin rounded, but its inner part more or less crested, with several granules directed inward; fingers as long as palm, sharply dentate on cutting edges, strongly pointed at tips; two and one longitudinal deep grooves on outer surfaces of movable and immovable fingers, respectively.
Ambulatory legs slender, sparsely covered with short plumose hairs; anterior margin of merus with a series of conical granules of good size. (Takeda, 1989)
Type locality: west side of Nominoura, Oshima Passage, Amami-Oshima, 45 m.
Range: Japan - Oshima Passage, Amami-Oshima and off Kushimoto, Kii Peninsula; 40-70 m.