in the Museum of the Smithsonian Institutior\ . 121 



broadex' than the propodus (jienult joint), and concave on the outer 

 surface ; ischium armed along the middle of its inner edge with a 

 sharp, prominent, spinous crest ; carpus thick, and only half as broad 

 as the propodus, which is greatly dilated within, and truncated, but 

 not grooved, at the broad anterior margin, against which the dactylus 

 folds ; dactylus rather stout, compressed, and rather longer than the 

 anterior margin of the propodus. Mandibles strong, much indurated ; 

 corona with its margin unevenly toothed, deeply cleft within, and 

 with the basal process as broad and half as high as the corona itself, 

 and having also a toothed edge. Appendages to the first two joints 

 of the abdomen in the male nearly similar to the corresponding parts 

 in the female. Caudal lamellae deeply sculptured. Of the appen- 

 dages to the penult joint of the abdomen, the outer lamellfe appear as 

 if composed of two pieces soldered together, the outer one of which 

 overlaps the inner ; while the inner lamellae are obliquely triangular. 

 Terminal segment of the abdomen very small. 



Qlypturus aeantJiocMrits Stimpson, Proc. Chicago Acad, of Sciences, I, 46. 



Dorsal suture A^ery deep. Front bearing an erect spine close to its 

 anterior extremity, and a sharp, curved spine on either side, over the 

 insertion of the outer antennae. Greater cheliped rather short and 

 stout ; ischium, meros, and caipus with their lower edge spinous ; 

 meros with two spines above, and no projecting lobe at the base 

 below ; carpus much shorter than the palm of the hand ; haml much 

 broader than the carpus, with three spines on the upper edge, and a 

 granulated area on the outer surface behind the base of the pollex or 

 immovable finger ; dactylus two-thirds as long as the palm of the 

 hand. Smaller cheliped nearly similar to the greater one in shape 

 and armature, but of less than half its size. 



In a female specimen, the length of the animal, exclusive of the 

 antennae, is 3.9 inches; length of the carapax, 1.02; length of car- 

 pus and hand taken together, and measured to the end of the dacty- 

 ius, 1.5 inches. 



This species is not uncommon among the Florida Keys. A 



