86 
to distinguish it from most other species. The stratum 
it occurs in, may probably be recognized by it in some 
other place. There are several places in Somersetshire 
where Ammonites are found compressed in a somewhat 
similar Clay. It is worth while to examine whether this 
or any other species of Patella occurs with them. 
Fig. 5 is from a shell, or rather the cast of one ina 
compact Limestone, found in a rolled mass among lumps 
of Chalk, Sandstone, and Gravel, at Pakefield, in Suf- 
folk ; the stone has a largely foliated structure ; it con- 
tains Telline, Ammonites, Vertebra, &c.* all compressed 
in the direction of the lamine, but this Patella is not so 
much so as in the Clay, therefore, it is but little cracked 
at the edges. 
ee 
PATEELA levis. 
TAB. CXXXIX.—Fig. 3 and 4. 
Spec. Cuar. Depressed, conical, smooth, shining ; 
base obovate; apex excentric. 
eee PB 
AA very smooth, even-formed. shell, about one-third of 
its length high and rather slender. 
I have two specimens of this. I believe it has hitherto- 
been overlooked ; the smaller one is. from Whitby, where 
it was found in that inexhaustible formation, the Alum 
Clay, which, independantly of its value in the formation 
of Alum, has attracted notice from the many larger fossil 
preductions, that in a manner eclipse this minute shell. 
The other specimen was found in Clay at Folkstone; I 
suspect it is a rare species. 
* The same stone produced.a Lingula figured at tab. 19. Mr. Thurtell 
sent me nearly the whole of it, and it has turned, out very productiye. 
