Davie, 1993
Carapace rectangular; greatest width between exorbital angles, or slightly behind; 1.25-1.3 times broader than long. Carapace slightly vaulted. Regions moderately defined. Lateral margins subparallel, slightly concave. Front c. 0.55 times fronto-orbital width; sinuous; lateral angles obtuse. Postfrontal lobes distinct; median lobes slightly broader than laterals. Epibranchial and branchial ridges prominent. Carapace surface relatively smooth. Setae very short, sparsely scattered over entire surface. Antennal flagellum small, entering orbit. Basal antennular segment not swollen. Interantennular septum moderately wide, c. 0.25 times width of front.
Chelipeds subequal, large and robust; merus with posterior border carinate, minutely granulate; without distinct subdistal spine; anterior border forming an acute, broad, sub-distal spine; carpus with inner angle not produced; inner margin granular; outer margin and dorsal surface striated. Upper surface of palm with three transverse pectinate crests (holotype with slight indication of a fourth). Primary crest composed of 15-20 tall, broad teeth (19 and 20 on holotype; 15 and 17 on smaller male). Secondary crest strongly developed; shorter than primary; with 10-13 smaller teeth. Outer surface of palm sparsely granular; with a very indistinct median longitudinal row. Outer surface of palm naked except for scattered tiny setae; and small patch in front of first pectinate crest. Inner surface of palm with a strongly raised granular vertical crest curving towards fixed finger. Fixed finger rounded on outer surface, with a triangular depression basally; length cutting edge c. 0.45 times length propodus. Ventral border of chela slightly concave at base of fixed finger. Dorsal surface of dactyl with 22-24 symmetrical calcareous tubercles, all distinct, closely spaced proximally, becoming well separated and more rounded towards tip, transversely widening medially. Fingers spooned, tips chitinous; curved inwards; a moderate page between cutting margins over distal half.
Ambulatory legs medium length; flattened; very broad; third pair the longest, c. 1.7 times maximum carapace width. Merus of third leg c. 2.4 times as long as wide; propodus c. 2.2 times as long as wide in holotype (2.4 in paratype male); dactyli c. 1.0-1.1 times length of propodus; about equal to length of propodi; stout, slightly recurved; terminating in acute chitinous tip. Merus anterior margin with acute sub-distal spine; unarmed terminally. Carpus with accessory carinae on upper surface. Propodus with accessory carina on inferior proximal portion of upper surface. Meri of legs 1-3 with scattered, small, distally directed prickles on cuticular terraces. Legs fringed with stiff bristles except on meri. Small patch of fur on ventro-distal border of propodi and ventral border of dactyli of first and second legs.
Male abdomen moderately broad; third segment the widest, first segment narrow. Segment six c. 2.6 times wider than long. Telson longer than preceeding segments; about as long as wide; evenly rounded.
Male G1 moderately stout, moderately curved; apical process corneous, strongly produced, lying at 90° to stem. Gonopore sub-terminal, tip cut away ventrally. Long setae mainly restricted to inner margin of distal third and around tip; mostly simple but some feathered setae proximally. (Davie, 1993)
Type locality: Shirahama, Wakayama Prefecture, Japan.
Range: Japan - Kochi (Ortmann, 1894a), Sagami Bay (Sakai, 1965b), Hakata Bay (Hashiguchi & Miyake, 1967), Sagami Bay and Yoron-jima (Sakai, 1976a), Nanki Shirahama (Miyake, 1983, Davie, 1993), Okukubi River, Okinawa (Shokita et al., 1998); Taiwan.