66 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



Description. — Carapace broadly ovate, elevated on median line, 

 posterior half semicircular, anterior half broadly triangular; surface 

 covered with unequal granules; four median spines, two gastric, the 

 posterior the larger, one large cardiac spine, one small, backward- 

 pointing intestinal spine; also a long, acuminate spine directed back- 

 ward at the distal end of the first abdominal segment; the anterior of 

 the median gastric spines is one of a transverse row of five ; in front of 

 the end spines of this row are two longer and sharper ; on the branchial 

 region are three small spines or tubercles forming a triangle; three 

 antero-lateral spines, one hepatic, and two branchial above base of 

 cheliped. Rostrum short, broadly triangular at base, ending in a 

 short, sharp, upturned spine, medially carinate. Supraorbital spines 

 prominent, separated by a depression; postorbital spines long, ex- 

 ceeding eye in large specimens. Antenna short, exceeding rostrum 

 but little; the basal article has, beside its terminal spine, a stout 

 spine pointing downward and forward in front of eye; peduncle not 

 attaining end of rostrum. The pterygostomian region has a row of 

 spines and spinules continued to antennal segment and including a 

 long spine at angle of buccal cavity. Sternum of male coarsely 

 granulate; abdomen of female with a median tubercle on third and 

 fourth segments. 



Chelipeds of male a little more than twice length of carapace; 

 ischium, merus and carpus granulate ; merus cylindrical; palm swollen, 

 shorter than fingers, and covered with fine scattered granules; digits 

 slender, curved inward, gaping at base only, where there is an en- 

 larged tooth on the dactyl. Chelipeds of female a little longer than 

 carapace, much smaller than in male; fingers not gaping. Legs long, 

 slender, cylindrical, roughened, except on the dactyls, with numerous 

 short, stout, appressed spinules; propodi and dactyli with a double 

 fringe of hair. 



The young are narrower, rostrum and dorsal spines longer, postor- 

 bital spine very small and pointing directly outward, and in speci- 

 mens 9 mm. long and less this spine is scarcely more than a tubercle. 



Measurements. — Male, holotype, length of carapace 25.5, width 24, 

 length of cheliped 58, of first leg 106 mm. Young male (18122), 

 length of carapace 10.5, width 8.7 mm. 



Range. — From South Carolina to Florida Keys and Gulf of Mexico; 

 West of Trinidad. Depth, 26 to 88 fathoms. 



Material examined. — See table page 67. 



