53 
disposed as to give that part of the spire nine sides : the 
turns are not easily distinguished from each other, except 
by the larger row of tubercles. 
Out of the upper marine stratum at Headon Hill, 
where it is abundant : it resembles Murex turbinatus of 
Brocchi, p. 443, but is evidently distinct. 
POT AM IDEvS ventricosus. 
TAB. CCCXLI. — Fig. 1. 
Spec. Char. Conical, turreted ; whorls ventricose, 
costated, transversely striated ; strife two or three 
upon each whorl, most elevated upon the costas j 
aperture orbicular, with an extremely short beak. 
A small well circumscribed species ; the striae that 
cross the costae upon the spire almost divide each of 
them into three tubercles : there are two more stria; upon 
the base which is convex ; the orbicular aperture appears 
to have no furrow even within its upper part • the colu- 
mella is smooth, and the beak obscure. 
This gregarious shell is very abundant in some parts 
of the so called upper marine formation of the Isle of 
Wight, accompanied with hardly any other shell except 
the last species. I have received it also from France, 
but without a name. 
POT AMIDES acutus. 
TAB. CCCXLI. — Fig. 2. 
Spec. Char. Conical, turreted ; whorls convex, bica- 
rinated ; carinse acute ; base convex, bistriated ; 
aperture orbicular, with a narrow short beak. 
A bout half an inch long ; an elegant, smooth, sharply 
carinated species. 
Discovered in a thin bed belonging to the lower fresh 
