(A. Milne Edwards, 1865)
The carapace elongate oval and its dorsal surface somewhat depressed; the regions are not at all defined, median gastric and branchial regions are faintly inflated, the former with curled hairs on either side but without any tubercles contrary to Xenocarcinus tuberculatus, the latter with an indistinct tubercle at the junction of the antero-lateral and postero-lateral borders. The cardiac region flat, without any tubercle at all (in A. M. Edwards' species, it seems to be mounted with two tubercles side by side). The posterior border is subtruncate, having an indistinct tubercle on either lateral angle.
The pseudorostrum is very long and beak-shaped, somewhat depressed and thickly covered with fine tomentum, its tip being bifurcated. The orbits are rounded, not very deep, eyes large; the intercalated lobe distinct. The basal segment of antenna is narrowed at tip and its antero-external angle armed with an indistinct tooth; the flagellum is very slender and short. The ridge of the pterygostomial region is armed with three tubercles. The merus of the external maxillipeds is produced at the antero-external angle; the exognath being broad and narrowed at tip.
Chelipeds are not stouter and longer than any of the ambulatory legs; the arm is armed with three spines on the anterior border, with one spinule on the posterior border near the distal end, wrist and palm unarmed and not much depressed; fingers not gaping, their prehensile edges indistinctly denticulated. First pair of legs is somewhat longer than the total length of carapace and rostrum; the merus is armed with four acuminate teeth placed along the superior border; carpus has an obtuse tooth in the middle of the superior border; the dactylus is slightly curved and its inner border has nine sharp teeth, of which three or four distal ones are especially larger. In other three pairs of legs, the merus has three more or less distinct teeth (in A. M. Edwards' species, the merus of these pairs seems to be unarmed); the teeth of the dactylus are eight in number and the distal three or four are prominent. (According to Gordon 1935, who examined the cotype of A. M. Edwards' species, the distal one or two teeth only are prominent in the dactylus of that species).
Abdomen of female has the first and last segments freely movable, the second to sixth being fused together, although the suture line between 2nd and 3rd segments is distinct. (Sakai, 1938: 325)
Type locality: Indian Ocean.
Range: Red Sea (Griffin & Tranter, 1986a); Persian Gulf (Stephensen, 1945, Griffin & Tranter, 1986a); Aldabra Island (Griffin & Tranter, 1986a); Réunion (Griffin & Tranter, 1986a); Cargados Carajos (Rathbun, 1911); Chagos Archipelago (Rathbun, 1911); Sri Lanka (Alcock, 1895a, Laurie, 1906, Griffin & Tranter, 1986a); Andamans (Alcock, 1895a); West Malay Peninsula (Griffin & Tranter, 1986a); Japan - Tanabe Bay (Sakai, 1938a, Takeda & Koyama, 1974), Kii Peninsula (Sakai, 1976a), Kushimoto (Miyake, 1983); Indonesia - Banda Neira and Kepulauan Kai (Griffin & Tranter, 1986a); 13-80 m.