I 
20 7 
exactly with those of Hampshire. Cliama lamellosa, of Lamarck, is evi- 
dently the same shell as cliama squamosa, of Brander, Foss. Hant.'N 0.86. 
Cliama calcarata of Lamarck, with distant transverse plicae, the superior 
of which is echinated with long canaliculated spines, he says, may per- 
haps be the same with the chama, No. 87, of Brander. Plate XIV. 
Fig. 13, represents one of these species which I possess, from Grignon. 
Lamarck observes, that Bruguiere was acquainted with C. lamellosa, 
and that it is that which he speaks of under the name of C. rugosa ; 
but that he confounds it with a chama which is not fossil, and which 
is figured in Lister and in Gualtieri. 
It is, however, probable that Lamarck is here mistaken. I find, 
among my chamas, one which certainly shows that there exists a fossil 
chama, to which the name C. rugosa is perfectly applicable. I also 
find one, which I believe to be fossil, and which exactly agrees with 
the recent shell figured by Lister, Tab. 217, Fig. 53, which has been 
considered as C. foliacea by Gmelin, and, perhaps, as C. rugosa by Bose. 
It is to the kind communication of Robert Scammell, Esq. of 
Plymouth, that I am indebted for an account of a stratum of fossil 
shells which he discovered at Haldon, or Hall-down, in the county 
of Devon. Haldon is a hill, very nearly 850 feet above the level of 
the sea, and is, from its northern to its southern point, about six 
miles in length, and nearly three in breadth. 
On the sides and summit of the hill, along with the vegetable mould 
are numerous flints : beneath these is, in some parts, a yellow, and 
in others a white clay, with a mixture of sand and silicious pebbles 
of various sizes, to the depth of three or four feet. In some parts is 
found a light brown sand, which, at the depth of about four fathoms, 
becomes a firm concretion. The substratum of Haldon is, in some 
places, chalk, and in others an extensive range of lime-stone. 
These strata terminate in others of various formation. Towards 
the river Ex, they unite with a long range of amygdaloid : they 
descend into the schist of Ashton ; which is here, as in many other 
