VENERICARDIA. PECTUNCULUS. 405 
there are upwards of thirty species: the Crag contains 
several, particularly a large and delicate shell, the Cardium 
Parkinsoni (Min. Conch. tab. 49). Others are peculiar to 
the London clay, as the Cardiwm semigranulatum, a beautiful 
shell, having the surface smooth, except on the posterior 
side, which is covered with strong ridges, beset with minute 
granules ; it is found in many localities (Min. Conch. tab. 
144). Among the silicified shells of the Shanklin sand of 
Devonshire, an elegant Cardium, C, Hillanum, (Min. Conch. 
tab. 14,) occurs. But one species is known in the formations 
below the Lias: the Cardiwm striatum, (Murch. Sil. Syst. 
tab. 6, fig. 2,) found in the Aymestry limestone. 
Venericarpia. Ly. p. 199.—These shells are abundant 
in the tertiary strata; one large species, V. planicosta, (Ly. 
p. 199, fig. 171,) is found in immense quantities in the 
clay and sand at Bracklesham Bay, in Sussex, from the 
young to the adult state; some examples are very large. 
and perfect. In the sand at Grignon, near Paris, the same 
shell is abundant, possessing the usual white and delicate 
aspect of the fossils of that celebrated locality of the Cal- 
caire grossier. Only one species has been noticed in the 
British secondary strata. 
Pectuncutus. Wond. p. 244, fig. 8—In the London 
clay at Bracklesham Bay, Highgate, Hordwell Cliff, and in 
the arenaceous limestone of Bognor rocks, an, immense 
number of the bivalve shells, called Pectunculi (little pectens), 
occur. Some of the French marine tertiary strata also 
abound in the same, and other species of this genus. In 
the above-mentioned Sussex localities, these shells are so 
numerous, as to be the most frequent fossils that come 
under the notice of the collector. They are readily known 
from their associates by their rounded equivalve shells, and 
the single arched row of teeth along the hinge, resembling 
