Stimpson, 1858
The carapace is much arched longitudinally, especially in its anterior part, and straight transversely. Towards the margins it is covered with short hairs, like the subhepatic and subbranchial regions, but the central parts of the carapace are smooth. There is a trace of a cervical groove, situated far backward, and at either end of this an irregular depression, covered with very short hairs, forms the most conspicuous marking of the carapace; there is further a transverse hairy line behind the front and the surface of the latter is obscurely divided by a short longitudinal sulcus.
The front is deflexed; its free edge regularly arched, but not notched in the middle in my specimen, as Alcock states; across its surface a transverse row of long hairs is to be observed, and this row is continued on the supraorbital margin and further laterally and backward along the antero-lateral margins of the carapace. The eyestalks are piriform, the eyes distinct, but in dorsal view of the animal nothing is seen from the eye, as this is chiefly developed on the ventral side of the eyestalks; its pigment is of a dark sepia tint, not black. The antero-lateral margins of the carapace are regularly arched and divided into three portions by two faint notches; the subparallel postero-lateral margins are much more obsolete and somewhat granulate, and at the transition between the anterior and posterior part the carapace reaches its greatest breadth, which is 1.3 times its length; the posterior margin is somewhat wavy, slightly convex in its middle part.
Antennulae folded transversely beneath the front. Antennae very short, peduncle free, not fixed to the front or to the inner orbital lobe. Epistome distinct. Lateral margins of buccal cavern greatly convergent backward. External maxillipeds broad, antero-external angle of merus conspicuously produced outward, exognath about half as broad as ischium, which latter is longitudinally grooved in the middle, about 1 1/2 times as long as broad, and slightly narrower than the merus.
Chelipeds subequal, bulky, but shorter than the ambulatory legs. Meropodite short, mostly smooth, but granulate towards the borders; upper border with a row of long hairs, which row terminates distally into a triangular, erect tooth. Carpus likewise granulate towards the margins, inner angle sharpened, but not produced, with a tuft of hairs projecting beneath it. Chela high; palm nearly as high as long and longer than the fingers, upper and under border rounded, not keeled, both surfaces smooth and shining, but the lower part of the outer surface is occupied in its proximal part by a few depressed granules, particularly in the left chela, similar granules are seen running in a longitudinal row near and parallel to the under border of the chela, and there are also some crowded and small granules near the upper border, which is provided with a row of long hairs, continued for some distance on the back of the movable finger; the fingers are short, not much curved, bisulcate both at inner and at outer surface, and the crenulations of the fixed finger are larger than those of the opposite one.
The ambulatory legs are moderately elongate and not much differing in length, the penultimate pair being little more than twice as long as the carapace; all the legs are fringed with coarse, yellow hairs, especially along the last three joints. Meropodites with some transverse rugosities on the upper surface, four times as long as broad, unarmed near the distal end; in the last pair the meropodite is hairless along the greater part of the anterior margin, the posterior margin is provided all along with numerous hairs, exceeding frequently in length the breadth of the meropodite. Dactyli of all the legs conical, falciform, shorter than preceeding joints, thickly fringed with hairs; those of the last pair are nearly straight, but not curved dorsally; their shape is somewhat obscured by the coating of long hair.
The first segment of the abdomen of the male is broadened, but clearly falls short of the coxae of the last pair of legs; the second segment is much narrower; the third again widens to the breadth of the first segment and projects into two somewhat acuminate prominences; the following segments gradually decrease in width, but increase in length; the terminal segment is semi-elliptical, longer than broad. (Tesch, 1918b)
Type locality: North China Sea.
Range: Andaman Sea (Alcock, 1900b); Japan - Bungo Strait and Kii Strait (Yokoya, 1933); North China Sea; Gulf of Thailand; Indonesia - west coast of Salawati (Tesch, 1918b); Torres Strait (Miers, 1886).