( 167 y^ 
X. Description of Mus Castorides, a new Species. By the Rev. 
E. J. Burrow, A.M. F.L.S. 
Read April 7th, 1812. 
Taave taken the liberty to lay before the Linnean Society.an 
account of a curious animal, which I believe has not been men- 
tioned by any writer on Natural History, and may, therefore, be 
thought worthy of the Society's notice. 5 Med 
The order to which it belongs is plainly that of Glires, and it 
appears to form the connecting link between the genera Castor 
and Mus; it is placed, indeed, so nearly midway between them, 
that it may be difficult to determine which has the better claim. 
Its teeth are those of the beaver, for there are four molares 
on each side in either jaw, and the incisors are simply wedged ; 
but it is deficient in the broad flat tail, which seems to con- 
stitute an essential generic character of the beaver, being so 
closely connected with the wonderful habits of life peculiar to 
that creature. id 
The occiput was broken, and a part of the muscles remained 
on the skull when I examined it; but as far as I could judge 
from this state, the conformation more nearly approaches that of 
the Norway rat, M. Decumanus, than that of the beaver ; parti- 
cularly in the smallness of the cranium, in the construction of the 
: anterior 
