THE CANCROID CRABS OF AMERICA 165 



Inhabits deep water off middle America, and Japan, the Indian 

 Ocean and the East Indies.^^ 



« 



KEY TO THE AMERICAN SPECIE3 OF THE GENU3 TRACHTCAECINUS 



A'. Tubercles of carapace furnished with smooth, flat, white granules. Cheli- 

 peds of male very unequal corallinus, p. 165. 



A^. Tubercles of carapace rough with acute or spine-tipped granules. Cheli- 

 peds subequal spinulifer, p. 166. 



TRACHYCARCINUS CORALLINUS Faxon 



Plate 72 



Trachycarcinus corallinus Faxon, Bull. Mus. Comp. Zool., vol. 24, 1893, p. 156 

 (type-localities. Bay of Panama, 546 and 695 fathoms, and off Acapulco, 660 

 fathoms; cotypes in M.C.Z. and U.S.N. M.); Mem. Mus. Comp. Zool., 

 vol. 18, 1895, p. 26, pi. A.— Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, 

 p. 599.— Not T. corallinus Balss, Arch. f. Naturg., vol. 88, 1922, p. 99, 

 wliich may be called T. balssi. 



Diagnosis. — Protuberances of carapace large, covered with smooth, 

 flat tubercles; chelipeds of male very unequal; outer surface of hands 

 smooth. 



Description. — Antero-lateral margin longer than postero-lateral. 

 General surface densely clothed with a dark brown coat consisting of 

 a multitude of close-set club-shaped setae; underneath this the shell 

 is smooth and white. Regions well marked; on the prominent parts 

 of each are groups of flattened, ivory white tubercles. The principal 

 groups are: two antero-lateral and one posterior median on the gastric 

 region; four in two pairs on the cardiac; five or six on each branchial; 

 and one crescentic on each hepatic region. Front with three acute 

 teeth, median twice as long as lateral. Preorbital tooth subrectangled, 

 edge denticulate. Behind the postorbital spine there are three promi- 

 nent teeth increasing in length successively; a minute tooth just 

 back of the largest lateral tooth. Posterior margin denticulate, 

 concave at middle. 



The end of the antennal peduncle does not quite reach the end of 

 the rostrum. Chelipeds of male very unequal, the larger may be 

 right or left; large chela smooth and ivory white; merus with a few 

 small teeth along upper margin, mostly near the two ends of the arti- 

 cle, and there are also a few still smaller teeth along the postero- 

 inferior margin; carpus inflated, upper margin armed with one strong 

 tooth and denticulate along its whole length; propodus somewhat 

 swollen, the finger bent down at an obtuse angle with the lower 

 border of the palm; usually two or three small tubercles or teeth on 

 upper margin of propodus, besides a tubercular process at articu- 



" If the three genera Peltarion, Trichopeltarion, and Trachycarcinus be retained, then Trichopeltarium 

 alcocki Doiiein (in Chun, Aus den Tiefen des Weltmeeres, vol. 2, 1903, p. 531, text-fig.) should be removed 

 from Trichopeltarion and be known as Trachycarcinm alcncki. 



