6 
VOLUTA tricorona. 
TAB. DCXIIL- fig. 2. 
Spec. Char. Ovato-rhomboidal, transversely striated, 
costated, spire short, acute; whorls crowned by 
three rows of short spines ; costae thin, as long as 
the volutions. 
This Volute is distinguished at first sight by its sharp ribs, 
each of which has three very short spines upon its upper part, 
and by the striae extending over the whole of the whorl. 
Collected from the clay at Primrose Hill, near Camden 
Town, with the two preceding species, by Mr. Wetherell : 
it is rare. 
Fig. 1. represents a young specimen of V. nodosa, Tab. 
399, for comparison ; it is from Highgate, where it was not 
uncommon. 
VOLUTA denudata. 
TAB. DCXIII.— Jig. 3. 
Spec. Char. Elliptical, ribbed; ribs short, thick, 
with a short spine near the upper part of each ; 
lower part of the whorl striated ; inner lip thick, 
extending far over the whorl ; columella with 
several irregular plaits. 
Will distinguished by its oval form, smooth surface and 
the thick inner lip ; it resembles Voluta rarispina, Lam.; 
but that shell has longer spines, a less regular form, and is 
much more strongly striated near the beak. 
This shell has long been known in the sandstone of the 
Bognor Rocks ; but until Mr. Bowerbank, with much per- 
severance, cleared a series of good specimens, it had not 
been recognised as a species ; one individual, cleared since 
the figure was engraved, measures three inches long. The 
same species has also been found at Brentford, but it is 
rare. 
