626 



Bulletin American Museum of Natural History 



[Vol. XLVIII 



widest part of the carapace. Posterior margin 2.3 mm. long, slightly curved; postero- 

 lateral margin thickened over the last pair of legs. Front 1.2 mm. wide, nearly 

 truncate, extremities curved; middle part bent under and ending in a point. 



Chelipeds shorter than first leg and very little stouter. Margins of chelipeds and 

 legs hairy. Palm increasing in width distally; fingers with a small tooth near base of 

 inner edges, tips curved toward each other. The legs are similar in form, their rela- 

 tive lengths represented by 2.3.1.4, the second longest, fourth very much shorter 

 than the others, its merus not reaching the middle of the merus of the third leg; in 

 all, the margins of the merus are subparallel, the upper margin of the propodus is 

 slightly arched, the dactylus is strongly curved, gradually tapering, but with a very 

 slender tip; the carpus-propodus of the second and third legs has a fringe of long 

 hairs on the posterior surface which proceed from near the upper margin. 



Fig. 1. Pinnotheres jamesi, left outer maxilliped of c? holotype, X 77.5. 

 Fig. 2. Pinnotheres jamesi, abdomen of cf holotype, X 18. 



The abdomen is very narrow and long, reaching to the buccal cavity; the first 

 two segments are linear, the third occupies little more than half the width of the 

 sternum, its ends rounded; fourth and fifth segments fused, the line of union partially 

 visible; the fourth tapers a little, the fifth is nearly square; the sixth is a little shorter 

 than the fifth and narrows slightly to the seventh, which is suboblong with rounded tip. 



This species belongs to the same group as P. concharum 1 ; it differs 

 from male concharum in its rounder carapace with pubescence along the 

 lateral angles instead of around the anterior half of the carapace, in the 

 broader front, the more convex posterior margin, the shorter and broader 

 legs, especially noticeable in the propodus, the longer and differently- 

 shaped abdomen. The outer maxilliped is akin to that of P. reticulatus, 2 

 from the Gulf of California, which is known only from the female and 

 has no other obvious relation to P. jamesi. 



'Rathbun, 1918, Bull. U. S. Nat. Mus., No. 97, p. 86, PI. xx, figs. 3-6, text-fig. 42. 

 *Op. cit., p. 93, PI. xxi, figs. 1 and 2. 



