102 
to cover its surface with a new protection in the most easy and rapid 
manner, and, commencing from a more or less central spot on the 
surface, enlarges the surface covered by adding new matter to the 
entire circumference of the first-formed part ; it continues this process 
without waiting to make the operculum as thick and solid as the one 
which was lost, until it reaches the size of the original, moulding 
itself on the opercular mantle, and adapting its form to the form of 
the throat of the aperture of the shell which it has to close. The 
change of form in the front of the restored and mended operculum 
is caused by the parts being moulded on the existing opercular mantle 
—consequently they have not the narrow front part which is found 
in the normal form, caused by that part having been formed when 
the animal had this part of a small size; and as it increases in size 
the whole opercular mantle moves forward, leaving the small tip of 
the operculum free, and useless to the animal, and therefore not 
necessary to be reproduced when the operculum is re-formed in the 
adult age of the animal. 
In the British Museum collection there is also a specimen of 
Cominia maculata with the operculum almost entirely reproduced, 
with the same alteration of the general form and position of the 
nucleus. These mended or reproduced opercula are always known 
from the normal operculum of the animal by being more or less 
irregularly formed and thinner in consistence. 
April 25, 1854. 
Dr. Gray, Vice-President, in the Chair. 
The following papers were read :— 
1. Notes on THE Hasits oF SOME INDIAN Birps. Part III. 
By Lieut. Bureess. 
Family Mervuipz. 
Subfamily Timatin 2. 
Genus TrmMatia. 
Trmatia Matcoumi, Sykes. Larece BABsuer. 
This Large Babbler, though not generally so common, I believe, 
as Timalia grisea, I have shot in the Deccan in the districts near 
the city of Ahmednuggur. It is gregarious in its habits, flying about 
in flocks of eight or ten. It lives much on the ground, seeking its 
food, which consists of grasshoppers, beetles, black and white ants, 
and other insects, under large trees and hedgerows, scratching up 
and turning over the dead leaves with its strong claws. It also feeds 
on grain; the stomach of one which I examined contained bajocee 
