PLEUROTOMA. 349 



Taken from fishes caught at the Banks, and one fine specimen 

 from a fisli caught in Massachusetts Bay. I liave a specimen also 

 from the coast of Norway. Halifax ( Willis') ; Marcouin {Bell) ; 

 fossil, Montreal {Dawson). 



The aspect of this shell is such that I was at first led to refer it, 

 doubtfully, to the genus Paluduia. It very greatly resembles Pal- 

 udiiia ponclerosa, Say. All doubt, however, on that point, has been 

 since happily removed through the kindness of Colonel Totten, who 

 furnished me with several specimens containing the sub-spiral oper- 

 culum. 



The remark of Deshayes, that Nalica is without an epidermis, 

 will not hold good in regard to this species, nor, indeed, to any of 

 the species found on our coast. He, however, was aware of the 

 small value of this characteristic, and alludes to a species then 

 under his eye, which I take to be N. heros, having the shape and 

 epidermis of Ampullaria, but the operculum of Natica. A specimen 

 sent to me by Dr. Lovcn was regarded by him as new, and he had 

 applied to it the name of N. exularis. 



Family TURRITID^, H. and A. Adams. 



Shell turreted, sub-fusiform ; aperture with the fore part chan- 

 nelled, straight, and often much produced ; outer lip detached at 

 the hind part from the body whorl, forming a sinus, or with the 

 marain fissured near the last whorl. 



'&' 



Genus PLEUROTOxlIA, Lamarck. 1799. 



Shell turreted, generally ribbed ; aperture terminating in a 

 straight, more on less elongated canal ; outer lip, at its posterior 

 junction, having a fissure or notch. 



Pleurotoma bicarinata. 



Fig. 186. 



Shell ovate-fusiform, turreted, dusky-white ; whorls convex, with two revolv- 

 ing ribs, and other less conspicuous lines and grooves ; notch of the lip shallow. 



Pleurotoma bicarinata, Couthouy, Best. Journ. Nat. Hist. ii. 104, pi. 1, fi<;. 11. — Gould, 

 Inv. 1st ed. 281, fig. 186. -De Kay, N. Y. Moll. 149, pi. 7, fig. 1 13. — StiiMPSON, 

 Check Lists, 5. 



Manjelia bicarinata, StimpsoNj Shells of New England, 49. 



