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 
strie ; columella, with a slight fold, white; with, unfrequently, 
three brownish bands. Operculum subtriangular, dentate around 
the margin. 
Length 13 to 19 mill., diam. 6 to 8 mill. } 
The animal is whitish with light purple dots, and its foot is 
bifureate behind. Very common from low-water mark to fifteen 
fathoms. 
New Hugland to Georgia. 
3. N. VIBEX, Say. Figs. 525 53. 
Journ. Philad. Acad. Nat. Sc., 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 costs, which are 
continued to the apex ; and about the same number of revolving 
lines, which are most prominent on the cost; suture moderate. 
Aperture oval; lip thickened without and within, with two to 
four prominent teeth internally ; 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. 
