Mollusks. 9151 
The lias is similarly worn by these Mollusca, and I believe by Nerita 
and Turbo littoreus, on the shore at Blue Anchor and Watchet. I 
observed a short time ago, in the Botanical Gardens and Victoria Park 
at Bath, a great quantity of grotesque freestone thrown up in heaps, 
as artificial rock-work. These stones were very extensively hollowed 
and perforated, apparently by the weather; besides, they had nume- 
rous swaller indentations and holes, like those in the Cannington stone. 
I afterwards saw an abundance of specimens in the same state on the 
oolite hills about Bath, loose on the surface or partly buried in the 
ground. 
Prof. Buckland to William Baker. 
Oxford, August 1, 1842. 
By the enclosed [letter of John Edward Gray as follows], which 
please to return to me, you will see that the evidence is all right. Did 
you ever notice how the Pholades make their holes? I believe the 
P. dactylus works by rasping with the tubercles of its shell. 
John Edward Gray to Prof. Buckland. 
Ilfracombe, July 29, 1842. 
My Dear Buckland,—I went on the beach this morning, and caught 
a gentleman, alias a Patella, making a hole. I put him in the lithmus 
paper, and the whole surface of the foot appears to be equally acid, 
and strongly so, for the paper became instantly bright red, as you will 
see by the specimen enclosed. Roget, who is here, was quite astonished 
at the instantaneousness of the change. We will try the nature of the 
acid and its strength. The place where the surface of the paper is 
corroded is where the foot first touched it.— Yours ever truly, J. E. 
Gray. 
William Baker to Prof. Buckland. 
Bridgwater, August 2, 1842, 
I return, with many thanks, Mr. Gray’s letter and its contents,—the 
lithmus paper. These have set me at work testing the secretions of 
other snails than hortensis, and I promise myself the pleasure of 
writing to you soon on this subject, and on the boring of the Pholades. 
William Baker to Prof. Buckland. 
Bridgwater, August 5, 1842. 
I wrote a note to Mr. Anstice this morning, giving him some account 
of the late discoveries relative to the excavating power of the garden 
snail, Patella, &c., and asked him if he did not think that the discovery 
of the acid in these Mollusca would give us reason to believe that the 
