402 SHELLS. [Cuar. XI. 
tinued 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, 
Ropert E. Grant. 
Sir J. Emerson Tennent, Sc. ec. 
