* 
204 Dr. Gapper on the Mammalia of Upper Canada. 
Arvicola Gapperi.t 
Meadow Mouse, with a tail more than half the length of the body ; short 
rounded ears ; the back and upper part of the head chestnut; sides and face 
yellowish brown; belly yellowish white ; chin and throat ash-coloured. 
TAB. IX. 
This Mouse is common on the steep banks of streams in the woods, 
burrowing like the former ; it is very fond of meat, and annoys the trapper 
by eating the baits set for the Marten, and by throwing the traps. 
It is about 4 inches long from the tip of the nose to the insertion of 
the tail; the tail itself 12 inch. The head is moderately large, and the 
nose on a line with the teeth: certainly it is not sharp-nosed like Dr. 
Richardson’s Arv. Noveboracensis, the only species which at all agrees 
with it ; the feet are whitish. I have caught several, all agreeing in colour, 
size, &e.t 
Mus decumanus (Linn.)* The Brown Rat. 
Introduced. Only found in the warehouses near Lake Ontario. 
Mus Musculus (Linn.)* The common Mouse. 
Introduced. Very common all over the country. A great many are 
frozen to death in the barns, where the native mice live in perfect security. 
Cricetus myoides (nobis.) Mouse-like Hamster. 
Hamster with a tail longer than the body; large eyes and ears ; upper 
half of the body mixed black and light reddish or yellowish brown ; 
lower half pure white. 
a TAB, X. 
Dental formula, incisors 2, canines 2, cheek-teeth 33. The cheek- 
teeth have long roots, and are crowned with several little blunt tubercles 
and convoluted ridges of enamel. It measures 32 inches from the tip of 
the nose to the insertion of the tail; the tail itself 3+ inches. The nose 
+ Dr. Gapper having left this new species unnamed, we take the opportu- 
nity of designating it by the name of the discoverer.—ED. 
{ Dr. Richardson to whom Dr. Gapper’s MS. has been communicated, 
remarks, “ this Arvicola differs from my Arv. Noveboracensis, in having more 
“ conspicuous ears, and is probably the animal Rafinesque named Novebora- 
“ censis ; but as his description is insufficient for correct discrimination, a new 
“ name had better be given to Dr. Gapper’s animal.—J. R.” 
