/S. I. Smith on American Crustacea. 145 



stout, the breadth being about equal to four-sevenths of the length ; 

 the outer surface of the propodus is flattened and smooth ; the inner 

 surface, in the middle and toward the base of the dactylus, and the 

 margins, are armed with scattered tubercles ; and finally, the fingers 

 are very stout, the outer edges are armed with small horny tubercles, 

 and the prehensile edges gape but slightly, and are armed with large, 

 irregular teeth. In the smaller cheliped, the merus is more slender 

 and does not quite reach the lateral margin of the carapax, and the 

 hand is very much smaller and more slender. 



The ambulatory legs ai-e stout and the carpal and propodal seg- 

 ments, and the meral on the angles below, are clotlied with long black 

 hairs, which are very conspicuous and fasciculated on the carjial and 

 propodal segments of the first and second anterior pairs. 



In the male, the abdomen is broadest at the third segment, from 

 which the margins converge regularly to the sixth, which is nearly or 

 quite as broad as long and only slightly narrowed for most of its 

 length, but sharply contracted just before the articulation with the 

 small and narrow terminal segment. In the female, the abdomen is 

 broadest near the articulation of the fifth with the sixth segment, and 

 the margins of the sixth segment are arcuate and converge rapidly to 

 the small, obtusely triangular terminal segment. 



The first pair of male abdominal appendages reach to the middle 

 of the penultimate segment of the abdomen, and their extremities 

 are slightly flattened laterally, thickly clothed with hair on the out- 

 side and terminated by a long, slender, hard and horny tip, which 

 curves outward for nearly half its length, then rapidly iipward, and 

 again outward at the end, forming thus about the third of a very 

 elongated spiral. From the under edge, just below the base of this 

 horny tip, there is a stout, straight process, which is soft and flex- 

 ible, and clothed at the extremity with hair. 



Four specimens give the following measurements : — 



Sex. 

 Male. 



Female. 



I have examined a large number of specimens collected at the Gulf 

 of Fonseca, west coast of Central America, by J. A. McNiel, and in 

 the Museum of the Peabody Academy of Science. 



Traks. Connecticut Acad., Vol. II. 10 April, 1870. 



