190 
G. deperdita, the only fossil species mentioned by Lamarck. Like this 
species, the Woolwich shells are ovato-transverse, and marked with 
very small transverse striae, indicating the stages of growth. They 
have three teeth at the hinge, and two compressed lateral teeth in one 
valve, with grooves for their reception in the other valve. Like the 
French fossil shells of this genus, the Woolwich also are entirely 
white, being without epidermis or animal matter. 
Having obtained a mass of shells of this genus, imbedded in pyrites, 
from the Isle of Wight, I was surprised at finding that their lateral 
teeth, like those of the Mactra solida , were transversely grooved, the 
penetrating teeth on the out, and the receiving teeth on the insides. 
Plate XIII. Fig. 5, represents the valve which is furnished with the 
penetrating grooved lateral teeth, from the Isle of Wight. 
CXVIII. Venericardia. An equivalved, inequilateral bivalve, ribbed 
longitudinally on the outside, with two thick hinge-teeth, disposed 
obliquely, and in the same direction. 
In some species, deserving, perhaps, as Lamarck observes, to be 
considered of another genus, there is but one tooth on one valve, and 
two diverging teeth on the opposite valve. 
These shells are strongly characterized by their having longitudinal 
ribs, as in the cockles and scallops. They are marine shells, and have 
two muscular impressions. 
The most beautiful species of this genus is V. planicosta, a remark- 
ably thick shell, obliquely cordated, with flat smooth longitudinal ribs, 
and which Lamarck describes as being sometimes three inches and a 
half in length. The shells of this species are found in the neighbour- 
hood of Paris, but are there but small. At Piedmont, and in the 
neighbourhood of Florence, they are found of the largest size : one 
specimen I have, which measures full four inches and a half. These 
fossil shells are found of a very handsome size on the Hampshire 
coast : Mr. Holloway, of the Custom-house, Portsmouth, has kindly 
favoured me with specimens from Selsea, one of which measures 
nearly three inches and a half in width. 
