1 20 Notes on North American Crustacea, 



inner lobe, and a denticulated posterior margin ; hand with a tuft of 

 hair between the fingers below. Ambvilatory feet everywhere hairy 

 on upper edge. Surface of meros of third pair also hairy. Size of 

 P. rupicola. 



Found at Mendicino, Cal., by Alexander As^assiz, Esq. 

 P«lyoiiyx iiiacroctieles. 



PorceUana mncrocJieles Gibbes, Proc. Am. Assoc. Adv. Sci., 1850, p. 171. 



This species Jives in the tubes of CJiaetopterus, along with 

 the woi'm and its other guest, Pinnixa chaetojpterana, on the 

 coast of South Carolina. 



HIPPOIDEA. 



MeBSftipes bartoadcsisas. 



Squilla iarbadensis ovalis Petiver, Pastrigrapliia americana, pi. ii, f. 9. 



Body oval. Carapax depressed, not narrowed anteriorly ; surface 

 nearly smooth, but anteriorly and towai'd the sides minutely lineo- 

 lated transversely as in other species. Front broad, undulated, with 

 a single broadly rounded median tooth ; margin minutely crenulated. 

 The lateral margins are ornamented with a rather broad marginal 

 stripe, which is transversely striated ; strise setiferous, and not intei*- 

 rupted at the middle as in some species. Inner antennae half as long 

 as the carapax ; the shorter flagellum being scarcely a tenth part as 

 long as the longer one, which is compressed and almost naked. 



Length of carapax, 0.84; breadth, 0.69 inch. 



Found at Barbados by Prof. Gill, and at Key Biscajne, 

 Fla,, by the late Gustavus Wurdeniann. 



THALASSINOIDEA. 

 Crlypturus. 



Olyptxirus Stimpson, Proc. Chicago Acad, of Sciences, I, 46. 

 Flagella of the antennulaj much longer than their peduncles. Ex- 

 ternal maxillipeds indurated ; meros and ischium not dilated, no 



