138 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



Type.— Cat. No. 46163, U.S.N.M. 



Dimensions. — Type male, length of carapace, 13.3 mm.; width of 

 carapacej spines excluded, 15.3 mm.; width, spines included, 15.5 

 mm.; width between outer angles of orbits, 10.8 mm.; width of front, 

 5.3 mm. 



Carapace very convex from front to back, less so from side to side; 

 regions scarcely indicated; surface smooth and shining, covered with 

 punctae and minute granules; postero-lateral margins slightly con- 

 vergent posteriorly, antero-lateral margins short, arcuate, and 

 armed with two small sharp spines, the anterior of which is about 

 one and one-half times its length from the orbit and points forward, 

 and the posterior of which is twice as far from the anterior spine and 

 is directed obliquely outward. In the single male specimen the 

 spines of the left side are shorter than those of the right side and are 

 bluntly rounded; they were doubtless broken off in some previous 

 stage. The anterior edge of the front is nearly straight, and close 

 behind and parallel to it there is a sulcus; sides of front obliquely 

 longitudinal, with a depression above the antenna. The orbital 

 margin has a finely granulated edge; the upper part slopes slightly 

 backward and is a little sinuous. 



The right cheliped is heavier than the other; a short, stout, acute, 

 curved spine is on the upper margin, distal to the middle; the carpus 

 is longer than wide and is armed with two spines, one at the inner 

 angle and one at the outer angle, the former the larger; the manus 

 is thick, its lower margin is arcuate, especially in the larger chela, 

 where the height of the manus is nearly equal to its superior length; 

 the fingers meet when flexed, their prehensile edges are irregularly 

 toothed; the larger dactyl bears a large backward-pointing basal 

 tooth in both sexes; tips of fingers crossing. In the large chela the 

 terminal half of the fixed finger and the entire length of the dactylus 

 below and two-thirds of its length above are a medium shade of 

 horn-color; in the small chela the terminal half of both fingers is 

 the same color. 



The ambulatory legs are slender, the last three segments hairy, 

 especially the dactyls, which are styliform, with the anterior or 

 upper margin nearly straight. 



The last five segments of the male abdomen form a triangle, 

 slightly constricted between the fifth and sixth segments. 



Differs from 0. indica x in having two lateral spines instead of 

 three, in the less advanced front, in the absence of a spine from the 

 lower, outer margin of the arm, in the absence of a third, or dorsal 

 spine, from the wrist, and in the shorter, stouter chelipeds. 



1 Carcinoplax longimanus indicus Doflein, Wiss. Erg. deutsch. Tiefsee-Exped. Valdivia, 189S-99, vol. 6, 

 1904, p. 114, pi. 35, figs. 1 and 2. 



