88 Notes on North American Crustacea. 



In this species, adapted to live in such shells as those of the 

 genera Conus and Stromhus, with long narrow apertures, the 

 body is much flattened, and the sternum greatly developed, 

 being broadly exposed" between the chelipeds, and showing the 

 ventral piece to which the outer maxillipeds are attached. This 

 would, perhaps, be considered by many as a character of ge- 

 neric importance, but it appears to us to be only a peculiar spe- 

 cific modification to adapt the animal to live under peculiar 

 circumstances. A modification which may occur in any genus of 

 Paguridce, and does occur in one other genus — instance Pagu- 

 rus platythorax. The species we have described shows fully all 

 the generic peculiarities of Paguristes, as does iho, platythorax 

 all those of Pagurus. 



P. depressus was found in a Stro7n'bus pugilis dredged in two 

 fathoms, sandy bottom, at the island of St. Thomas, by Theo. 

 Gill, Esq. 



l^piropag-urtis dispar, nov. sp. 



Carapax smooth and glossy, naked. Eyes rather longer than in S. 

 spiriger, but not over-reaching the tip of the acicle. Ophthalmic 

 scales narrow. Chelipeds slender, smooth, glabrous, sparsely ciliated, 

 unequal in size, the left one being much more slender, though but little 

 shorter than the right ; left hand with slender fingers as long as the 

 palm. Right hand a little longer than the left, and twice as broad and 

 thick ; fingers short, not more than half the length of the palm, and 

 coarsely toothed within. Ambulatory feet much longer than the cheli- 

 peds and over-reaching their extremities, smooth and hairy ; dactylivery 

 slender, not dilated. Feet of the fourth pair almost simple ; penult 

 joint with no scabrous surface, but a few corneous marginal denticles. 

 Length about one inch. Colors mostly faded in our specimens ; the 

 hands are, however, pale orange, loosely reticulated with thread-like 

 crimson lines, on the white fingers as well as on the palm. 



This small species was found in the white shell of a Natica. 



