20 
* 
CYPRINA Morrisii. 
TAB. DCXX. 
Spec. Char. Transversely oval or oblongs regu- 
larly convex, rather compressed ; beaks pro- 
minent; anterior slope sharp-edged, the pos- 
terior slope rounded ; lunette sunk, undefined; 
principal hinge-tooth in the right valve broad. 
Syn. Venus incrassata. Wether ell, Foss, of the 
London Clay, 8$c , Phil. Mag. and journ. 
v. ix. 463. V. Morrisii, ib. v. x. 239. 
A smooth thin shell of variable proportions, generally 
oval; the depth of the undefined lunette gives a charac- 
ter to its form, which when once noticed is easily recog- 
nized. It occurs in the lower beds of the London Clay, 
sometimes called Plastic Clay, either in sand, as at Re- 
culvers, Herne Bay and Pegwell Bay, on the coast of 
Kent, and at Plumstead, Watford and Reading ; or in 
indurated sandy marl, as at Bognor, and near the bottom 
of the well on Hampstead Heath. 
When I made the alteration in Mr. Wetherell’s list, 
quoted above, which Mr. Morris suggested, the hinge 
was still unknown, and consequently I referred the shell 
to the wrong genus; a number of specimens from the 
sandy beds and from the Hampstead Well have been 
since worked out, so as to enable me to correct this error. 
Figs. 1 — 4. represent specimens from Herne Bay, 
some of which are in Mr. Bowerbank’s cabinet ; fig- 5, 
a variety from Pegwell Bay ; fig. 6, a small variety from 
Boughton, near Canterbury: it is a cast in Calcedony ; 
many such were found, and some of them contained 
water. 
