402 
SHELLS. 
[Chap. XI. 
tiimed to clink audibly within the distance of twelve feet 
during the whole meeting. These small animals were indivi- 
dually not half the size of the last joint of my little finger. 
What effect the mellow sounds of millions of these, covering 
the shallow bottom of a tranquil estuary, in the silence of 
night, might produce, I can scarcely conjecture. 
In the absence of your authentication, and of all geological 
explanation of the continuous sounds, and of all source of fal- 
lacy from the hum and buzz of living creatures in the air or 
on the land, or swimming on the waters, I must say that I 
should be inclined to seek for the source of sounds so audible 
as those you describe rather among the pulmonated vertebrata, 
which swarm in the depths of these seas — as fishes, serpents 
(of which my friend Dr. Cantor has ' described about twelve 
species he found in the Bay of Bengal), turtles, palmated birds, 
pinnipedous and cetaceous mammalia, &c. 
The publication of your memorandum in its present form, 
though not quite satisfactory, will, I think, be eminently cal- 
culated to excite useful inquiry into a neglected and curious 
part of the economy of nature. 
I remain, Sir, 
Yours most respectfully, 
Robeet E. Grant. 
Sir J. Emerson Tennent, $e, fyc. 
