8 NATURAL HISTORY OF SELBORNE. 
LETTER Te 
TO THE SAME. 
THE fossil-shells of this district, and sorts of stone, such as have 
fallen within my observation, must not be passed over in silence. 
And first I must mention, as a great curiosity, a specimen that was 
ploughed up in the chalky fields, near the side of the Down, and 
given to me for the singularity of its appearance, which, to an 
incurious eye, seems like a petrified fish of# about four inches long, 
the cardo passing for an head and mouth. It is in reality a bivalve 
of the Linnean genus of Mytilus, and the species of Crista Galli ; 
OSTREA CARINATA. 
called by Lister, Raste/lum,; by Rumphius, Ostreum plicatum 
minus; by D’Argenville, Auris Porct, s. Crista Galli, and by 
those who make collections, Cock’s Comb. Though I applied to 
several such in London, I never could meet with an entire specimen ; 
nor could I ever find in books any engraving from a perfect one. 
In the superb museum at Leicester House permission was given to 
me to examine for this article ; and, though I was disappointed as 
to the fossil], I was highly gratified with the sight of several of the 
