136 S. J. Smith on American Crustacea. 



below the superior margin, there is an oblong, depressed space which 

 is very conspicuous as seen from above. This dejDression exists in 

 6r. minax but is not at all conspicuous. The propodal finger is very 

 long and slender, curved upward at the extremity, and the prehensile 

 edge ai'med with a large tubercle near the middle and another near 

 the tip, which is deeply excavated for the reception of the dactylus. 

 The dactylus is very slender, the basal portion nearly straight, the 

 extremity strongly hooked downward and inward, the superior edge 

 smooth, and the prehensile edge armed with several large tubercles. 



The ambulatory legs are long and much more slender than in the 

 allied species, the meral segments being quite narrow. 



The abdomen is quite similar to the abdomen of G. pugnax, but is 

 somewhat narrower. 



The females differ from the males in having the carapax narrower 

 and more convex, and in the branchial regions being tuberculose along 

 the lateral margins. 



Several specimens give the following measurements : — 



" Canals at Para, South America, October or November, 1858 ; 

 Caleb Cooke" (Collection Peabody Academy of Science). 



G-elasimus pugilator LatreOie. 



Ocypoda pugilafor Bosc, Histoire naturelle des Crust., tome i, p. 197, 1802; (pars) 

 Say, Journal Academy Nat. Sci , PhQadelphia, vol. i, p. 71, 1817, p. 443, 1818. 



Gelasimus pugilator LatreiUe, Nouveau Dictionnaire d'Histoire naturelle, 2 ^ edit, tome 

 xii, p. 520, 1817; Desmarest, op. cit., p. 123 ; Edwards, Annales des Sciences natu- 

 relles, 3"^e serie, Zoologie, tome xviii, 1852, p. 14, pi. 4, fig. 149; Stimpson, Annals 

 Lyceum Nat. Hist., New York, vol. vii, p. 62. 



Gelasimus vocans, DeKay, Natural History of New York, Crust., p. 14, pi. 6, fig. 9 ; 

 (pars) Gould, Report on the Invertebrata of Massachusetts, p. 323 (non Cancer 

 .vocans Linne). 



Plate IV, figure 7. 



This IS at once distinguished from any of the east coast species, 

 except G, subcj/lindricus, by the rectangular outline, swollen and 



