OSTREA carinata. 
TAB. CCCLXV. 
Syn. O. carinata. Lamarck Hist. Nat . VI. 21 6. 
Spec. Char. Elongated, pointed at both ends, 
arched, plaited ; sides flattened ; middle 
longitudinally cariniformed ; plaits numer- 
ous, angular, and regular ; ears two, variable. 
•if- 
The pointed ends, the depth of the valves, and regu- 
larity of the plaits, are characters by which this Oyster 
may generally be known : the curvature and ears are 
variable, the anterior or exterior ear being often obsolete 
in old shells. 
A series of specimens of various ages have been selected 
for the illustration of this species : it will be seen that the 
curvature varies considerably. Fig. 1 is the most elon- 
gated variety : it is from the grey Marl below the Chalk 
at Folkstone in Kent : the remainder are silicious : they 
are from the green Sand of Chute Farm near Longleat 
Park. An extremely elegant French specimen, nearly 
double the size of any here figured, was some time ago 
given to me by Mr. de Gerville, with intentions that 
render his friendship more dear to me than even his nu- 
merous presents do : it is from the Chalk Marl, and 
is so much curved as to form three-quarters of a ring : 
the outer ear is obscure, but the inner is very large. A 
figure of this specimen is given in Mr. G. B. Sowerby’s 
work upon the Genera of Shells. The Rev. Mr. White 
in his Natural History of Selburne, has figured a similar 
specimen : and the same species probably is given by 
