PRELIMINARY LIST OF THE MAMMALS OF NEW YORK 319 
1856 Arvicola dekayi Audubon & Bachman, Quadr. N. Am. 3:287. 
1884 LEvotomys rutilus gappert Merriam, Linn. soc. New York. ‘Trans. 
Pe] 3: 
1891 Lvotomys gapperi Merriam, North American fauna. 30 July 
TO|ItG UNO IS JDh 1110) 
1898 LEvotomys gapperi Mearns, U.S. Nat. mus. Proc. 21: 349. 
Type locality. Region between York and Lake Simcoe, Ontario 
Canada. 
Faunal position. While the common red-backed mouse is a typical 
Canadian animal, in sufficiently cool, damp localities it penetrates con- 
siderably to the south of the normal geographic limits of the boreal zone, 
flabitat. In the northern part of its range this mouse is found in 
almost every variety of surroundings, but further southits habitat becomes 
more limited. In the Canadian zone it is one of the most widely dis- 
persed mammals, in the northern partof the transition zone it is restricted to 
damp woods, while in the lower part of the transition zone it is never found 
far away from cold streams, wooded sphagnum bogs and cedar swamps. 
Mr Charles H. Batchelder has recently described the conditions under 
which the red-backed mouse occurs in the transition zone of eastern 
Massachusetts. He says, ‘“‘ What these favorable conditions are, is the 
most interesting question connected with the animal’s [local] distribution, 
but it is not one that can receive a positive and final answer. Neverthe- 
less there are some characteristic features that are common to almost all 
of the places where I have found it [in southeastern New England]. 
One may look for it with some confidence in almost any large tract of 
wet ground that retains its moisture through the summer, but is not subject 
to serious floods, and which bears a growth of woods sufficiently heavy to 
afford a dense shade, so that the ground beneath and the roots of the trees 
are covered with a deep carpet of sphagnum. If the older trees have 
been suffered to die a natural death, and their stumps and fallen trunks 
lie slowly rotting on the ground half-concealed by the sphagnum, the 
chance of finding it is certainly not lessened. One of the most evident 
peculiarities of such a spot as this, in southern New England, is that the 
dense shade and the abundant evaporation maintain a temperature dur- 
ing the hottest summer weather that is far below that of the surrounding ~ 
country. In these respects of coolness, moisture and shade there is a 
striking resemblance to the woods ZLvotomys gapperi inhabits in extreme 
northern New England and other parts of the Canadian zone. 
“The places where I have found it differ considerably in their appear- 
ance, chiefly according to the kinds of trees with which they are wooded. 
