52 



VI. Concholepas. An oval vaulted univalve, the apex inclined to the 

 left side, with two teeth and a sinus at the base of the right edge. 



No shell of either of these genera appears to have been found 

 fossil. 



VII. Calyptrea. A conoidal univalve, with the apex erect, entire, and 

 rather pointed, the cavity furnished with a spirally convoluted lip or 

 diaphragm. 



It is to this genus, as Calyptr&a trochiformu, that Lamarck refers the 

 fossil which Solander, in consequence of its possessing a kind of spire, 

 has considered as a trochus, denominating it Trochus aptrtus; and in 

 another state, tuberculated and more depressed, Trochus opercularis. 

 Fossil. Hautoniens. Tab. ix. Fig. 1,2, 3. These are found in the Hamp- 

 shire cliffs, with the other fossils, figured in the work of Brander, 

 just referred to. They are also found, in a very fragile state, between 

 Woolwich and Blackheath, in the parish of Plumstead, in Kent. La- 

 marck also describes another shell, found with the former at Grignon, 

 which he considers as a distinct species, C. crepieularis, from its not being 

 completely orbicular, and from its having its spire bent downwards, as 

 in the crepidute. 



Another species of this genus, Plate V. Fig. 10, found in the Essex 

 cliffs, appears exactly to agree, in its form, with Patella sinensis, Lin. as 

 figured by Lister, Tab. LXLVI. Fig. 39. It forms a depressed cone, 

 with a circular base and mammillary apex, and should perhaps be distin- 

 guished as Calyptr&a sinensis. Some specimens of this shell, which I have 

 obtained from the neighbourhood of Harwich, have their upper part 

 completely invested with a mineralized spongy, or alcyonic mass. 



VIII. Conus. A turbinated, convoluted, inversely conical univalve : 

 the aperture long, narrow, toothless, and not contracted at the base. 



Of the genus Conus, Lamarck describes four species, as found at Cour- 

 tagnon and Grignon : C. Antediluvianus, C. deperditus, C. turritus, and 

 C. Strombo'ides. 



C. deperditus, distinguished by its channelled spire, I have also ob- 



