No. 10.— /Some Facts in regard to the Distribution of Certain 
Mammals in New England and Northern Neio York. 
By Charles F. Batchelder. 
At the present time so little is known in a definite way about the 
details of the distribution of most of the smaller North American 
mammals that any exact information of this nature concerning the 
less abundant species cannot fail to be of value. The following 
somewhat fragmentary notes therefore need no apology for their 
presentation. 
Synaptomys cooperi Baird. Cooper’s Lemming Mouse. 
In the summer of 1895 I was surprised to find this species in the 
Adirondack Mountains, at Beede’s, Essex Co., New York. On 
August 161 set thirty-six “ cyclone” traps, baited with rolled oatmeal, 
in some low ground, wooded chiefly with large yellow birches, sugar 
maples, and beeches, with more or less thin, tall undergrowth (chiefly 
Acer spicatum Lam. and A. pennsylvanicum L.), and with many 
mossy, rotten logs and stumps scattered over it. A dozen of the traps 
were along the edge of some wetter, almost swampy, gr ound where 
more of the larger trees had been cut and there was a thick growth 
of small trees, chiefly Acer spicatum. Two days later, August 18, I 
found an adult male Synaptomys cooperi caught in a trap set at 
the foot of a large rotten stump in the edge of the swampy ground. 
Three days later I caught an immature female near by, also in the 
edge of the swampy ground, in a trap placed under a rotten log. 
Two days after this I got still a third, another adult male, this time 
in the open drier part of the woods, thirty or forty yards from the 
wet ground. On this date (August 23) I set over forty more traps 
in the most promising spots throughout all the rest of the adjoining 
land that was similar in character, but, although I continued my 
daily visits to them until August 28, they yielded no more Synaptomys.. 
This ground was exactly like various other places in the neighbor¬ 
hood, where I had done much trapping in previous summers, and I 
