THE CANCROID CRABS OF AMERICA 



283 



ARGENTINA. — Market of Buenos Aires; from stomach of Acan- 

 thistius patachonicus; U. S. Bureau of Fisheries; 1 male (32566). 



La Plata; February, 1902; Bisego collector; 1 male (Mus. Pauiista, 

 383). 



Puerto San Antonio West; April, 1920; A. Carcelles, collector; 

 3 females (60963); gift of Buenos Aires Museum. 



Mar del Plata; 1 young male (60966) ; gift of Buenos Aires Museum. 



Argentina; exact locality not given; 1910; A. Hrdlicka; 1 female 

 (50528). 



PATAGONIA. — Exact locality not given; d'Orbigny collector,' 

 2 CO types (Paris Mus.). 



PLATYXANTHUS COKERI, new species 



Plates 120-122 

 Platyxanthus crenulatus Rathbxjn, Proc. U. S. Nat. Mus., vol. 38, 1910, p. 540, 

 not pi. 39, fig. 2; not P. crenulatus A. Milne Edwards 1879. 



Type-locality. — Near mouth of Rimac River, Peru; R. E. Coker; 

 one male holotype (Cat. No. 40410, U.S.N.M.). 



Diagnosis. — Carapace very convex. Outer frontal teeth directed 

 obliquely outward. Merus of maxillipeds longer than broad. Fingers 

 in the old as long as middle length of palm. Major dactylus without 

 large basal tooth. 



Description. — Closely allied to P. crenulatus, to which I formerly 

 assigned these Peruvian specimens. The carapace is more convex 

 than in crenulatus; the granulation is simUar, but the granules are 

 thickly interspersed with punctae plainly visible to the naked eye; 

 the hepatic and the epibranchial ridge are thick and blunt and per- 

 sist in the old; there is also a single but less evident protogastric 

 ridge; in the young only is there a trace of the second or short ridge. 

 The first of the antero-lateral lobes is longer than the second and is 

 separated from the orbital angle by a distinct sinus; the anterior 

 margin of the two lateral teeth slopes inward and forward instead of 

 inward and backward as in crenulatus; postlateral margin more sinu- 

 ous. Outer teeth of front wider than inner and directed obliquely 

 outward; median sinus subtriangular, wider than in crenulatus, lateral 

 sinuses broad, asymmetrical. Inner supra-orbital tooth forming an 

 obtuse angle ; orbital fissures short and shallow ; suborbital teeth lobi- 

 form, outer one low, inner one large, inclined inward and nearly as 

 advanced as the outer frontal tooth; outer angle of orbit less advanced 

 than the tooth below it. The first and second truncate lobes of the 

 antero-lateral margin are bordered by shallow crenulations; the last 

 three sinuses are broadly V-shaped. 



Merus of outer maxilliped longer than wade, the anterior (or 

 antero-external) margin being more oblique than in crenulatus; the 

 merus is intermediate in shape between those of orhignyi and crenu- 

 latus. The merus of the chelipeds has a strong, acute, upstanding. 



