1S] 
TROCHUS duplicatus. 
TAB. CLXXXI.---Fig. 5. 
Spec. Cuar. Conical ; sides of the whorls concave ; 
a double deeply crenulated carina round the 
base ; umbilicus open, with a tuberculated 
margin ; aperture quadrangular. 
ae aii 
Tue upper edge of each whorl is crenulated as well as 
the carine: the concave space between the two edges is 
plain; the whole surface is shining. The umbilicus, 
which has about seven tubercles around it, forms a strong 
and remarkable character. 
From Little Sodbury, along with the last. 
TROCHUS dimidiatus. 
TAB. CLXXXI.---Fig. 4. 
Spec. Cuar. Conical; base convex, with a cari- 
nated margin ; upper part of the whorl con- 
cave, with an entire carina in the middle ; 
aperture pentangular. 
EE ————— 
Tus smaller whorls are convex; the last formed 
ones only shew the carine and concave spaces between 
them : the carina in the middle of the upper part of the 
whorl projects so much as to give the shell a square 
clumsy form: the columella is direct and solid. 
I have received a single example of this from Little 
Sodbury, along with the two latter species; it is dull and 
rather rough on the surface. 
