24 
GKYPHAEA obliquata. 
TAB. CXII. —Fig. 3. 
Spec. Char. Oblong, .slightly involute, oblique; 
right side an obscure lobe; lesser valfe irregu- 
larly ovate, externally concave. 
1 — 
The curvature of this shell rarely forms one whole circle, 
the beak turns to the right side; it is seldom sharp, but 
often truncated by the surface of adhesion to other bodies 
when it was young : it is a broader shell than the last, 
with rounded sides. 
This species does not seem to mix with the preceding, 
and by a little use will always be discriminated ; it either 
belongs to another rock formation or another part of the 
same stratum ; information relative to the places they are 
found at, and other circumstances, may ripen our know- 
ledge as to these particulars. 
Most of my specimens of this species are out of blue 
Lias ; one of them has minute young ones attached to it, 
these are very flat, nearly circular, a quarter of an inch or 
less in length, without the least appearance of curvature, 
although they show more beak than young Oysters in 
general do. Part of the shell of this is replaced by Silex, 
with those concentric marks so frequent on the green Sand 
Fossils ; it is in blue Lias, from St. Donat’s Castle, Gla- 
morganshire, by the Rev. W. Traherne. 
