OF 8ELB0RNE. 9 
one into the other, the alternate flutings or grooves, and 
the curved form of my specimen being much easier expressed 
OSTREA CARINATA. 
by the pencil than by words, I have caused it to be drawn 
and engraved.^ 
Cornua Ammonis are very common about this village."^ 
^ This is not the analogue of the cock's comb oyster, but belongs to 
a different species which has not any liv'ng analogue, so far as is known. 
The figures given above, which are copied from those of the original 
edition, represent a shell of the Ostrcea carinata of Lamarck, so called on 
account of the strong ridge or keel along the middle of each of its 
valves. Though both are plaited oysters, the plaits or folds in each 
are disposed in a different manner : in the cock's comb oyster they are 
in the longitudinal direction of the shell, which, moreover, is rounded in 
its general outline ; in the keeled oyster they pass transversely on each 
side from the ridge or keel. 
The statement in the text, that White's specimens were obtained in 
chalky fields, renders it necessary, as Mr. Bennett has judiciously re- 
marked, to caution the reader against regarding it as a chalk fossil. 
The fields below the chalk downs at Selborne, though white in the 
appearance of their soil — locally termed white malm — belong in truth 
to the formation known to geologists by the singularly inappropriate 
name of green sand. To this formation the keeled oyster is peculiar ; 
and it appears even to be limited, as a fossil, to the upper green sand, 
the stratum on which the village of Selborne is built, and of which the 
immediately adjacent enclosures consist. — En. 
^ The Rev. J. Mitford has said the same thing of Keynsham, between 
Bath and Bristol, adding that " This has given rise to a fabulous legend, 
which says that St. Keyna, from whom the place takes its name, resided 
here in a solitary wood, full of venomous serpents, and her prayers 
converted them into stones, which still retain their shape." — See Espin- 
ella's Letters from England, vol. iii. p. 362. — Ed. 
