Typhlocarcinops transversa

Tesch, 1918

This species is broader than any other known species of the genus, the breadth of the carapace measuring nearly 1 1/2 times its length. The surface of the carapace is somewhat pubescent, more so the female than in the male, and densely fringed with long, club-shaped hairs along the margins, especially the antero-lateral ones; on the other hand are front and eyestalks nearly destitute of hairs. The front is longitudinally grooved, which groove bifurcates distally; for the rest there is scarcely any trace of regions on the longitudinally-vaulted carapace.
The free edge of the front is on the whole straight, slightly wavy in anterior view, and longer than either orbit. This small orbit is, as usual, completely filled by the firmly-fixed eyestalk, which is of a semicircular shape and provided with a faint speck of pigment near the distal end; this pigment is stronger in the female specimen. As is of general occurrence in the Rhizopinae, the orbits and eyestalks do not form an interruption in the general outline of the carapace; the antero-lateral margins are directed nearly straightly outward near the orbits, then curve back, and form three blunt teeth, only visible, however, after removal of the row of hairs and the pubescence covering them. These teeth are separated by very wide interspaces; the median one, which is of the same build as the first, is situated nearer to the third than to the first; the third tooth is the smallest, crest-like, longitudinal, and marks the transition to the postero-lateral margins of the carapace, that are somewhat converging backward; it is near these margins that the carapace is roughly granulate. The posterior margin is convex, thickened.
Antennulae and antennae are shaped quite like those of genus Typhlocarcinus. The epistome is distinct, vertical, its free edge not crenulate or wavy; the septum between the endostome ridges is very distinct. Lateral margins of buccal cavity parallel. Merus and ischium of external maxillipeds pubescent and granulate, as is also the exognath; external maxillipeds completely closing the buccal cavity; merus subquadrate, as broad as, but shorter than, ischium, antero-external angle somewhat produced; exognath about one-third the width of ischium.
Chelipeds strong, longer than the first pair of ambulatory legs in the male. Meropodite with upper border unarmed, but granulate and hairy, like inner border, under surface with numerous granules. Wrist short, granulate and hairy near the rounded inner margin. Chelae equal, but larger in male than in female, sharply keeled above; in the female both surfaces of palm are entirely covered with a short pubescence, intermingled with longer hairs at outer surface, and, together with this pubescence, the palm is everywhere granulate; in the male the same occurs, but a patch in the middle of the outer surface is devoid of pubescence and entirely smooth; the fingers are shorter than the palm, for the greater part glabrous, greatly compressed, sharply crenulate at inner margins, back of mobile finger and under margin of opposite one with a row of hairs, which are much longer on the movable finger; in the male the fixed finger does not present a longitudinal row of hairs.
Ambulatory legs not much elongate. Outer margin of carpo- and propodite and inner margin of latter fringed with the usual, club-shaped hairs; penultimate pair of legs with some scattered hairs only, propodites of this pair longest, narrowing distally; dactyli as long as preceeding joints, styliform, hairy, little curved, those of last pair shortest, straight, but curved upward near the tip.
First abdominal segment of both sexes very broad, reaching to the bases of the last pair of legs, but almost linear, third segment in male little produced laterally, remaining segments gradually narrowing.
This species in its general appearance seems nearest to T. marginata, of which no figure as yet is published, but in the new species the antero-lateral margins are obtuse, and present three blunt, widely-separated teeth instead of the apparently closely-grouped, denticulate teeth of Miss Rathbun's species; the carapace of T. transversa is wider, the eyes are not prominent and dark. In both these species the fronto-orbital distance is approximately one-half of the greatest breadth of the carapace. (Tesch, 1918b: 212)

Type locality: Bay of Bima, north coast of Sumbawa, Indonesia, 13-31 m.
Range: Japan - off Tsushima (Takeda, 1973c); East China Sea (Takeda & Miyake, 1968c); Indonesia - Sumbawa (Tesch, 1918b), Selat Sunda (Serène, 1964); 13-103 m.

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