S. I. Smith on American Onifitacea. 137 



highly polished, dorsal surface of the cara})ax, and by the inner sur- 

 face of the basal portion of the propodus of the larger cheliped being 

 evenly rounded and beset with small scattered tubercles, but with no 

 indication of an oblique tuberculose ridge. From G. suhcylindricus, 

 it is readily distinguished by the carapax being narrower and its pos- 

 terior margin straight, by the hand in the larger cheliped of the male 

 being margined with a slight crest on the outside of the superior 

 edge, and by the narrow male abdomen. 



It seems to be abundant from the Giilf States to Massachusetts. 

 At New Haven, Conn., it is very common upon muddy beaches, but 

 is not usually associated with G. pugnax, which prefers salt-marshes. 

 There are specimens in the Museum of Yale College, collected at 

 Egmont Key, West Florida, by Col. E. Jewett, and at St. Augustine, 

 by Col. W. E. Foster and H. S. Williams ; and in the collection of 

 the Peabody Academy of Science, there are specimens from Savan- 

 nah, Georgia, from Bluffton, South Carolina, and from Nantucket, 

 Massachusetts, those from the last locality collected by Dr. A. S. 

 Packard, Jr. 



A series of specimens give the following measurements : — 



G-elasimus snbcylindricus Stimpson. 

 Annals Lyceum Nat. Hist, New York, vol. vii, p. 63, 1859. 



Plate IV, figure 6-6''. 



This species has a general resemblance to G. pugilator, but the 

 body is much broader, not so much narrowed behind and veiy con- 

 vex, being in foct much like G. gibhosus. The male abdomen and its 

 appendages are, moreover, very unlike any other species wliich is 

 known to me. 



