Fes., 1912. MAMMALS OF ILLINOIS AND WIsconsin — Cory. 463 
Description — Ears short and broad; general color sooty brown; the 
back, more or less of the under parts and the 
furred portion of the interfemoral membrane 
frosted with ashy white, the white frosting most 
pronounced on the back; interfemoral membrane 
furred for about half its length, the rest bare; 
teeth 36; four front teeth between canines in 
upper jaw; tragus short and bluntly rounded at the tip. 
Measurements — Total length, about 4 in. (101.6 mm.); tail, 1.62 in. 
(41 mm.); foot .33 in. (8 mm.). 
This species ranges throughout Illinois and Wisconsin and is com- 
mon about Chicago. I have examined specimens from Chicago and 
other localities in Cook and Du Page counties; it has been reported 
from the Illinois River and St. Louis, Mo. (H. Allen, J. ¢., p. 111); 
Wood states it is common in Champaign County (/. ¢., p. 595). 
Wisconsin specimens have been examined from Milwaukee, Wal- 
worth, Burnett, Polk and Dodge counties; Snyder reports it abundant 
at Beaver Dam, Dodge Co. (J. c., p. 126); and Jackson gives it as very 
common in most localities in the southern part of the state (J. c., 
ps 33) 
The Silver-haired Bat is found practically throughout the United 
States and is enormously abundant in some localities. Harrison 
Allen states that an old house at Seneca Point, near Charlestown, 
Cecil Co., Md., was inhabited by more than 10,000 Bats supposed to be 
mostly this species, 9,640 of which were killed by actual count.* 
In describing their habits Dr. C. Hart Merriam says: ‘‘Like many 
other bats, it has a decided liking for water ways, coursing up and 
down streams and rivers,. and circling around lakes and ponds. In 
some places its habit of keeping directly over the water is very marked. 
At Lyon’s Falls it is exceedingly abundant, particularly just below the 
falls. I have stood, gun in hand, on a point on the east bank of the 
river, and have seen hundreds passing and repassing, flying over the 
water, while during the entire evening not more than two or three 
strayed so far that if shot they would fall on the land. Several that 
were wounded and fell into the water, at a distance of fifteen or twenty 
feet from the bank, swam ashore. They swam powerfully and swiftly, 
for the current is here quite strong and would otherwise have carried 
them some distance down stream. 
“Next to water courses, the borders of hard-wood groves are the 
favorite haunts of the Silver-haired Bat. By standing close under 
the edge of the trees one sees many that at a little distance would pass 
* Monograph Bats N. Amer., 1864, p. xvii. 
