134 >iS'. I. Smith on American Crustacea. 



differs only in being, somewhat smaller and in having the fingers 

 slightly more incurved at the tips so as to fit nicely the buccal area. 

 Length of carapax, 11-2"""; breadth of carapax, 16"4""" ; rato, 1 : 1-46. 

 Length of left cheliped, 25 -0'"'". Length of right cheliped, 21-0""", 

 The specimen, which was examined while alive, was very active and 

 used both hands with equal facility. 



With this single remarkable exception, I have found only the 

 slightest variations in examining carefully more than a liundred 

 specimens, 



G-elasimus rapax, sp. nov. 



Plate II, figure 2. Plate IV, figure 3. 



Male. The carapax is very much like that of G. pugnax^ but the 

 front is narrower, the upper edge of tlie superior orbital border is 

 sinuous and not so transverse as in that species, being directed some- 

 what backward, the border itself is wider and its lower edge is not 

 so abruptly curved above the base of the ocular peduncle. 



In the larger cheliped, the anterior surface of the merus is smooth. 

 The superior surface of the carpus is minutely tuberculose and the 

 inner surface is crossed by a slight, oblique ridge which is nearly 

 smooth. The basal portion of the propodus is much stouter tlian in 

 G. pugnax and considerably longer than the digital portion, the 

 superior and exterior surface is thickly covered with small tubercles 

 and the inner surface is much as in G. pugnax, but the superior 

 margin is curved more abruptly, and farther downward at the extrem- 

 ity of the depression into which the carpus folds, and there is a line 

 of bead-like tubercles, along the border next the base of the dactylus, 

 which are very much larger than in G. pugnax. The projiodal finger 

 is short and stout and considerably curved upward, the inferior edge 

 is smooth and rounded, and the prehensile edge is much as in G. 

 pugnax, but the tubercles are larger. The dactylus is slout, curved 

 toward the extremity and the tip hooked by tlie end of the other 

 finger, the superior margin is tuberculose toward the base and mar- 

 gined on the outside for nearly half its length, and the prehensile edge 

 is as in G. pugnax but there are four or five large tubercles close 

 together near the base. 



The ambulatory legs are quite similar to those of G. pugnax 

 but seem to be much less hairy. 



The abdomen is as in G. pugnax. 



Length of carapax, 12-6'"™; breadth of carapax, 190'""'; ratio, 

 1 : 1-51. Length of hand, 28-2""'' ; breadth of hand, 10-8'""\ 



