THE CANCROID CRABS OF AMERICA 459 



Description. — Body covered with a short, thin down. Carapace 

 smooth to the naked eye, microscopically granulate ; very convex from 

 front to back, much less so transversely. Gastric and hepatic regions 

 feebly indicated. Margin of front slightly arcuate, nearly straight, 

 divided by a small median emargination. Inner angles of orbit small, 

 and though more elevated than the front, project scarcely at all 

 laterally, superior fissures obsolescent, outer sinus broad and shallow; 

 outer angle a small triangular tooth not prominent. Behind it on the 

 antero-latera! margin are three other lobes or teeth, the second a 

 small shallow lobe, the third an obtuse-angled tooth or lobe with 

 short anterior and long, somewhat convex posterior margin which is 

 nearly longitudinal; last tooth dentiform, short, elevated. Basal 

 antennal article short and broad. 



Cheiipeds of male long, strong, unequal; a broad lobe on upper 

 margin of merus and at inner angle of carpus. Manus elongate, 

 increasing in width distally, margins a little convex. Fingers long, 

 deflexed, with little or no gape, prehensile teeth uneven, a larger one 

 at base of major dactyl, dark color not covering tips of fingers or base 

 of immovable finger. Ambulatory legs slender, unarmed, pubescent 

 toward extremities. 



Color. — Fingers except extreme tips fresh-blood red, tips white. 

 (Henderson.) 



Measurements. — Male (9759), length of carapace 17.6, width of 

 same 23.8, fronto-orbital width 14.6, width of front 7 mm. 



Range. — North Carolina and Gulf of Mexico to Cape Frio, Brazil; 

 15 to 124 fathoms. 



Material examined. — See table, page 453. 



TETRAXANTHUS RUGOSUS. new species 



Plate 185 



Type-locality. — Off Sand Key, Florida, 120 fathoms; holotype, 

 male. Cat. No. 60828, U.S.N.M. 



Diagnosis. — Moderately convex. Third and fourth lateral teeth 

 prominent. Two blunt teeth on inner margin of carpus of cheliped. 

 Legs spinulous. 



Description. — Narrower, more hexagonal and less convex than the 

 preceding. Front bilobed, lobes little oblique. The rectangular 

 tooth at inner upper angle of orbit projects sideways beyond the 

 front. Of the four antero-lateral teeth (including the orbital) the 

 second is placed close to the first, both together occupying much 

 less of the margin than the third tooth. Third and fourth teeth 

 large, triangular, prominent, tips tuberculiform, the posterior margin 

 of the third tooth sinuous instead of convex. Posterior margin of 

 carapace more concave than in hidentatus. 



