95 
OSTREA Meadei. 
TAB. CCLIL— Figs. 1 and 4. 
Spec. Char. Tongue-shaped, thick, elongated ; 
attached valve yery concave, longitudinally 
undulated ; the other plain and flat. 
A very rugged irregular shell, but generally much 
elongated ; its substance is compact, in which it differs 
from somewhat similar recent ones, whose laminae en- 
close large cysts. The flat valve in the specimen before 
us has the lateral crenulations near the hinge, common 
in this genus, very conspicuous. 
I was favoured with this specimen some years ago 
by Thomas Meade, Esq. but do not know the locality ; 
it is probably from Somersetshire. I have not been 
able to identify it with any species hitherto described. 
OSTREA tener, 
TAB, CCLII.— Figs. 2 and a. 
Spec. Char. Depressed, elongated, thin, nearly 
plain ; attached valve, nearly flat, with a ca- 
naliculated beak. 
This slender, and consequently fragile Oyster, is ge- 
nerally much longer than wide ; it is often much dis- 
torted, so, as it is never deep, the upper valve frequently 
becomes concave : both valves are free from radiating 
undulations, and possess an uncommon degree of 
smoothness, although they are composed of imbricated 
laminae. The pointed beak of the upper valve included 
