34 AMERICAN MARINE CONCHOLOGY. 



body-whorl. Whorls six or seven, flattened; surface granulated 

 by prominent vertical lines and about ten revolving impressed 

 lines. Suture impressed, with a prominent shoulder on the whorl 

 near it. Aperture oval ; lip sharp, sculptured with revolving 

 striae; columella, with a slight fold, white; with, unfrequently, 

 three brownish bands. Operculnm subtriangular, dentate around 

 the margin. 



Length 13 to 19 mill., diam. G to 8 mill. 



The animal is whitish with light purple dots, and its foot is 

 bifurcate behind. Very common from low-water mark to fifteen 

 fathoms. 



New England to Georgia. 



3. N. vibex, Say. Figs. 52, 53. 



Journ. Philad. Acad. Nat. Be, ii. 231. 1822. 



Nassa fretensis, Perkins, Bost. Proc, 117. 1869. 



Shell solid, ovate, short ; whorls six ; body-whorl with from ten 

 to twelve vertical, undulating and prominent costre, which are 

 continued to the apex ; and about the same number of revolving 

 lines, which are most prominent on the costae ; suture moderate. 

 Aperture oval; lip thickened without and within, with two to 

 four prominent teeth internal]}' ; pillar lip arched, with a broad 

 flat callus, which forms a process directed upwards towards the 

 suture on the upper portion of the body-whorl, and is slightly 

 granulated at the base. Spire short, rapidly attenuated to an 

 acute apex; canal very short. Color ashy-white to pale reddish- 

 brown, with darker colored revolving bands. 



Length 13, diam. 8 mill. 



The animal has a large foot, auriculate in front, and narrowed 

 behind, about one-half longer than the shell. The broad head is 

 maculated with dark gray, and the upper part of the body with 

 snow-white, and a broad longitudinal median band of the same 

 color; beneath, whitish. 



A rather larger variety, with less acute spire, more numerous 

 and narrower ribs, more prominent revolving lines, thinner and 

 smaller callus and darker color, has been recently described as 

 N. fretensis. I give a copy of the figure (fig. 53). From low 

 water to fifteen fathoms. 



Cape Cod, Massachusetts, to West Indies. 



