Feb., 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, I. c., p. iii); 

 Wood states it is common in Champaign County (I. c., 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. (/. c., p. 126); and Jackson gives it as very 

 common in most localities in the southern part of the state (I. c, 



P- 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. 



