GENUS DOLIUM. 5 
often widened, feebly convex, and separated by furrows hardly 
apparent ; suture very distinct, slightly channeled towards the 
last whirl. The aperture is large, subovate, marked by 
transverse, slightly projecting bands, which correspond to the 
furrows of the exterior. ‘The interior of this cavity is of 
a fawn color. The right lip is thin, everted, a little undu- 
lated, and adorned with a white band the whole length of 
its interior, with the exception of the edge, which is of a 
deep brown. ‘The left lip is spread out over the body of the 
shell; it is very thin, transparent, and terminated below by 
a projecting plate which covers the umbilicus, and seems also 
to form a part of it. The columella is smooth, polished, 
and forms at the left of the umbilicus a thick rib, marked 
by transverse strie, which terminates at the emargination of 
the base. 
Length 5 inches. Width 32 inches. 
Inhabits the Channel, the Mediterranean, the equatorial 
seas, the seas of India, of Africa, and of America. 
This shell is remarkable on account of its form, being gen- 
erally more elongated than that of other species, and particularly 
by its coloring, which makes the transverse ribs to appear as if 
enameled with smal] white spots, for the most part curved in the 
form of a crescent. 
The mollusk of this shell inhabits rapid waters, and appears 
pretty quick in its movements. The ground of its color is a 
bluish white, covered with irregular spots of a red brown, bor- 
dering upon the violet. The foot is colored in the same man- 
ner beneath, but above, it is furrowed with wide triangular 
radiating bands. The tentacule are doubly ringed with brown. 
