222 AMERICAN JOURNAL 



Pleurotoma bicarinata, Pease. — Plate 15, fig. 23. Proc. 

 Zool. Soc. London, 1862. 



Description. — T. turrita, elongata, alba ; anfr. 6, undique 

 striis elevatis clathratis, anfr. ultimo carinis duabus, spiraque 

 unica ornatis, carinis eminentioribus, anfr. e carinis ad suturas 

 obliquis, juxta suturam vix angulatis, anfr. ultimo inter carinis 

 piano ; labro expanso, crenulato ; canali tortuoso, recurvo ; siuu 

 perangusto, profundo, rima rotunda terminate. 



Dimensions. — Long. 10, diam. 5 mill. 



Habitat. — Kingsmill Is. 



Shell turrited, elongate, white ; whorls 6, clathrated through- 

 out by longitudinal and transverse elevated striae, the last whorl 

 ornamented with two and the spire with one keel, keels very 

 prominent, crenulated on their edge, the whorls descending ob- 

 liquely from the keels to the suture, the middle of the last whorl 

 between the keels plane, at the sutures slightly angulated ; lip 

 expanded, on its surface radiately ridged ; canal twisted, re- 

 curved ; sinus a very narrow deep slit, terminating in a round 

 hole. 



Remarks. — This bold and exquisitely sculptured species is 

 unlike any of the Family. Its chief peculiarity is the form of 

 its sinus. 



