55 
from Dover and Folkstone . 
An interesting specimen of an undescribed species of Inoceramus was found in 
this stratum (PI. 1. fig*. 3.) It is filled by and partly imbedded in flint; suf- 
ficient, however, is visible to allow of its being* thus characterised. 
Inoceramus. 
Gen. Char. A free, unequal- valved, inequilateral, eared bivalve. 
Hinge, containing* an internal ligament and formed 
of alternate ridges and furrows, across the lower 
margin of the eared part. 
Inoceramus Lamarckii. 
Spec. Char. The valves roundish, slightly indented longitudinally, 
and having strong round transverse ribs, with inter- 
posed strim. 
Mr. Sowerby having as a tribute of respect distinguished the larger species of 
this genus as Inoceramus Cuvieri, a grateful consideration of the advantages 
yielded by the classification of Lamarck has led to the assumption of his name 
for the designation of the present species. 
From the numerous fragments found in this and the other chalk strata, it is 
evident that many species of this genus existed, differing very much in form and 
size. Thus in this species the plane of the hinge, nearly agreeing with that of 
the valves, the shell is nearly equivalved ; but in another species the hinge plates 
are placed at right angles with the valves, the teeth being disposed perpen- 
dicularly. Hence in this latter species the larger valve must be involutely 
curved, to admit of the apposition of the hinge plate of the other, perhaps, 
smaller and flatter valve. Other specimens show that the hinge plates are dis- 
posed in various intermediate oblique directions, in other species of this curious 
shell. 
Terebratula The species found in the two former beds. 
Alcyoriium A botryoidal, enteriform species, and many other bo- 
dies allied to this genus. 
The chalk of this bed appears to be distinguished by its greater weight and 
by its gritty feel, which gives the idea of its being blended with minute particles 
of sand. 
