126 
CRUSTACEA. 
tubercles on the upper and under side, and scattered 
tubercles on the inner ; pincers stout, tuberculous 
on their outer edges and obtusely dentate on their 
prehensile side ; four posterior pair of feet greatly 
flattened; terminal joint with some long hairs; 
tarsi long, sharp, and very spinous. 
Length, as measured in two specimens, about 
Wo- inches; supposed to have been brought from 
Surinam by Dr. Herring. 
This species may, perhaps, terminate that section 
of the true Grapsi of M. Edwards, in which the 
third joint of the external maxillary feet is longer 
than broad ; from these we will separate the follow- 
ing species of M. Edwards’ second division, and 
place them in the 
Genus Pachygrapsus. 
Maxillipedum artieulo tertio baud longiore quam lato, 
externe dilatato; fronte leviter depressa; corpore quadrato 
vel postice retracto; coetera Grapso similis. 
In these, the third joint of the external maxillary 
feet is as broad as long, more or less rounded on 
its outer side, and generally considerably dilated at 
its anterior inner angle, the front is not vertical, but 
simply inclined ; the body is either nearly square 
or retracted behind ; it is generally thicker, and its 
parietes firmer than in the Grapsi of the first divi- 
sion, and the anterior feet are usually very large 
and strong. 
O * 
