Takeda & Nagai, 1983
Carapace slightly broader than long, rather rounded and evenly convex fore and aft; dorsal surface very thickly covered with short soft hairs so as to be distinctly velvet-like, true surface being observed only with removal of them; one or two longish setae on each areola; deep symmetrical grooves make a more or less labyrinth appearance; protogastric region rather small, with a median longitudinal depression, its inner part being nearly continuous with oblong epigastric region; meso- and metagastric regions united together, only with a pair of rod-like groove on their median part, being transversely diamond-shaped; cardiac and intestinal regions only shallowly isolated and longitudinally diamond-shaped as a whole, its anterior end being confluent with metagastric region; an oblique rectangular areola at postero-lateral part of transverse diamond or at antero-lateral part of longitudinal diamond, and thus a large longitudinal diamond is formed on median part of carapace; antero-lateral areola deeply isolated laterally from protogastric region and postero-laterally from large diamond mentioned above, and traversed by two oblique deep grooves parallel to antero-lateral border of carapace. On denudation, dorsal surface of carapace quite smooth and ill-defined, only with very shallow interregional furrows, in spite of distinct grooves made by tomentum.
Front strongly declivous, being deeply incised medially; inner end of each lobe just outside the median notch most strongly produced, rather angulated and fringed with several setae of variable length; frontal and supraorbital borders directly continuous, without interruption or depression, but with sharp angle. Supraorbital border not raised at all, having two shallow depressions; infraorbital border fringed with setae, and bears a shallow depression just under external orbital angle which is not prominent at all. Basal segment of antenna very short, filling only proximal half of hiatus between front and infraorbital angle; second segment freely movable in distal half of hiatus. Eyestalk densely covered with a velvet-like tomentum and embedded in deep fossa, cornea being chiefly ventral. Subhepatic region unarmed.
Antero-lateral border of carapace with an arched wide lobe and a granule-tipped tooth, the latter of which is separated from the former by a deep notch; in holotype the arch of main lobe is rather regular, but in paratypes there is a low mound with a blunt small granule. Postero-lateral border of carapace weakly convex for its anterior part and convergent posteriorly.
Third maxilliped rather sparsely and uniformly covered with long setae; ischia and meri of both sides narrowing distally and proximally, respectively, and thus leaving a rhomboidal hiatus, in which large distal three segments of both sides are folded.
Chelipeds distinctly unequal and covered with a velvet-like tomentum and sparse longish setae, being fringed with longish, more or less comb-like setae on inner margins of merus and carpus and both margins of palm; merus rather small and hidden beneath carapace for its most part, its upper margin being sharply crested, with a subdistal notch; carpus larger and distally ornamented with a submarginal groove; its inner upper margin rather distinct, with a row of some granules and setae, its distal end being tipped with a blunt conical granule of good size; palm heavy, especially in larger cheliped; its outer surface thickly covered with conical granules which are not markedly different in size; fingers short.
Ambulatory legs stout and covered with a characteristic tomentum and setae of variable length just like chelipeds; setae arranged on margins of meri and carpi and also on upper surfaces of propodi and dactyli; each merus unarmed, having a subdistal notch on anterior margin.
In life the tomentum is uniformly light chocolate brown and the true surfaces of the carapace, chelipeds and ambulatory legs are purple. (Takeda & Nagai, 1983)
Type locality: Shiono-misaki, Kushimoto, Kii Peninsula, Japan.
Range: Japan - Shiono-misaki, Kii Peninsula (Takeda & Nagai, 1983).