142 S. I. Smith on American Crustacea. 



propodus is short and compressed, the outer surface is flat and granu- 

 lous, the inferior edge is angular and has a very slight, granular 

 margin on the outside, the superior edge is rounded and granulated, 

 and the inner surface is armed with a slight, oblique, tuberculose 

 ridge extending from the inferior edge to the shoi-t depression into 

 which the carpus folds. The digital portion of the propodus is much 

 compressed, straight and very slender, the inferior edge is nearly 

 smooth, the prehensile edge is only very obscurely tuberculate and 

 has a single, very slight tooth near the middle, and the tip is slender, 

 acute and slightly upturned. The dactylus is compressed, very 

 slender, straight for two-thirds its length and the terminal portion 

 regularly curved downward, the superior edge is rounded and slightly 

 granulous toward the base, and the prehensile edge is as in the other 

 finger, except that the tooth is smaller and nearer the base. 



The smaller cheliped is smooth and unarmed, the merus is slender 

 and triquetral, the carpus is short and rounded, the basal portion of 

 the propodus is quite short and thick, and the fingei's are slender. 



The ambulatory legs are long, very slender and nearly naked, and 

 the meral segments are very narrow. 



The sternum is very broad and very convex. The abdomen is 

 scarcely at all contracted at the second segment, and it tapers slightly 

 to the extremity of the sixth ; the first and second are very short, the 

 the third is about twice as broad as long, the fourth, fifth and sixth 

 are completely anchylosed into one piece, and the seventh, or last, 

 forms very nearly a semicircle. 



Length of carapax, S'S"'"' ; breadth of carapax, 14-4'"'" ; ratio, 1 : 1*79. 

 Length of hand, 24-8™"^ ; breadth of hand, 8 •2""". 



I have seen only one specimen, which was collected at the Gulf of 

 Fonseca, west coast of Central America, by J. A. McNiel (Collection 

 Peabody Academy of Science). 



Family, Gecarcinid^. 



Cardiosoma Latreille. 



In this genus the abdominal appendages of the male present, in 

 some cases at least, good specific characters. In all the species which 

 I have examined, the appendages of the first segment are very stout 

 and nearly straight organs reaching beyond the middle of the abdo- 

 men, articulated at their bases Avith a large and hard semicircular 

 plate, which arches round the intestinal canal and joins the abdomen 

 on each side, and armed at their extremities with slender, horny tips. 



