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 Linnaean genus of Mytilus, and the species of Crista Galli; called by Lister, Rastellum; by Rumphius, Ostreum plicatum minus; by D'Argenville, Auris Porci, s. Crista Galli, and by those who make collections cock's comb. Though I applied to several such in London, I could never 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 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 shells themselves in high preservation. This bivalve is only known to inhabit the Indian Ocean, where it fixes itself to a zoophyte, known by the name Gorgonia. The curious foldings of the suture, the one into the other, the alternate flutings or grooves, and the curved form of my specimen being much easier expressed by the pencil than by words, I have caused it to be drawn and engraved.
Cornua Ammonis are very common about this village. As we were cutting an inclining path up the Hanger, the labourers found
