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GRYPH^A Columba. 
TAB. CCCLXXX1II. —Fig. 1 and 2. 
Spec. Char. Ovate rounded, expanded pos- 
teriorly, smooth ; beak attenuated, incurved, 
oblique. 
Syn. Gryphaea columba, ham. Hist. Nat. VI. 
pt. 1. 198. Knorr petr. Vol. 111. tab . £>. 
HI. c. 
Perhaps this is the smoothest species of Gryphaea 
known ; except towards the margin, there is hardly a 
single sharp projecting line of growth to be found ; the 
anterior lobe is small, but well defined ; the left or 
upper valve is more or less square in form, and largely 
waved, its posterior edge is very thick, flattened, and 
striated near the hinge, every where else the edge is thin 
and sharp ; the depth of the attached valve is about half 
it3 width ; it is obtusely keelformed ; the surface of 
attachment is very minute, at the point of the involute 
beak. 
If we may judge by the characters of the stone this 
shell is preserved in, it belongs to some part of the Green- 
sand formation contiguous to the Chalk : the only 
British specimen that I have ever seen, was given me 
many years ago by my lamented Friend Mr. Cunnington, 
who obtained it from Northamptonshire ; it is represented 
in the lower figure. The upper figure is taken from a 
French specimen from Mans ; it is in a much better state 
of preservation than the English one. 
Fig. 2. is the variety b of Lamarck, with a striated 
beak, it is also from Mans ; I have added it to shew the 
hinge which approaches that of Chama in appearance, 
since it has the rudiments of a tooth, and the hinge pit 
very much curved. 
