284 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



subdistal tooth; the distal extremity also is acutely pointed. Tooth 

 at inner angle of carpus strong. Fingers more elongate than in 

 crenulatus; in the old the dactylus of both chelae exceeds in length 

 the middle length of the palm; the major dactylus has no large basal 

 tooth as is present in both sexes in crenulatus; the dark color of the 

 fingers in the female of medium size covers little more than the distal 

 half except alongside the white prehensile teeth; in the old male the 

 color has almost disappeared, but it seems tb have been much less 

 extensive than in the smaller specimen. The felt-like covering of 

 the dactylus of the ambulatory legs is interrupted by five longitudinal 

 lines of short hairs. 



Young. — A young male, 31.9 mm. wide, shows the following differ- 

 ences from the adult: The first and second lobes of antero-lateral 

 margin are cut into irregular, tuberculiform denticles; the second 

 lobe, especially on the right is in its entirety more dentiform than in, 

 the adult. 



Measurements. — Male holotype, total length of carapace 59.8, 

 width of same 88.3, fronto-orbital width 26.7, frontal width 13.6 

 mm. 



Range. — Peru. 



Material examined. — 



PERU. — R. E. Coker collector; received from Peruvian Govern- 

 ment: Southeast of Caleta Colon, Bay of Paita; 7 to 8 fathoms; 

 soft mud; taken in boat beam trawl; April 13; 1 young male (40411). 

 Near mouth of Rimac River; thrown on beach by strong sea; Feb- 

 ruary 4, 1907; 1 male holotype, 1 female returned to Peruvian Gov- 

 ernment. Callao; identified by a photograph received from R. E. 

 Coker. Pisco, on beach; July 7, 1908; 1 female (40409). 



Paita; October 8, 1926; W. L. Schmitt; 1 young (62714). 



PLATYXANTHUS PATAGONICUS A. Milne Edwards 



Plates 123-125 



Platyxanthus paiagonicus A. Milne Edwards, BuU. Soc. Philom., ser. 7, vol. 3, 

 1879, p. 107, pi. 1 (type-locality, Patagonia; type in Paris Mus.). 



Diagnosis. — Surface ver^^ uneven, antero-lateral margin with 

 numerous indentations. Frontal lobes not deeply subdivided. Merus 

 of maxilliped broader than long. Dark color covering about two- 

 thirds of dactylus of chelipeds. Ambulatory legs narrow. 



Description. — Carapace uneven; hepatic region defined by broad 

 deep furrows; anterior mesogastric region distinct; sin-face covered 

 with a flat pavement of dense granules and innumerable pimctae; 

 toward the margins and on the ridges coarsely granulate; an hepatic 

 and an epibranchial ridge, subparallel; a short high epigastric ridge, 

 a protogastric ridge directed inward and a little backward; a ridge pro- 

 ceeding obliquely backward from the last lateral tooth and finally turn- 



