468 Field Museum of Natural History — Zoology, Vol. XL 



Type locality — Philadelphia, Pennsylvania. 



Distribution — Greater portion of the United States and southern 

 Canada, from the Atlantic to the Pacific, except the southern parts 

 of the Gulf states where it is replaced by a slightly different form. 



Description — Ears short and furred at base ; tip of tail extending 

 slightly beyond interfemoral membrane; wings and interfemoral 

 membrane naked; general color of body sepia brown, paler on 

 under parts, the back often showing a tinge of yellowish or cinna- 

 mon; fur when rubbed showing darker brown at base; number 

 of teeth in upper jaw 14. 



Measurements ■ — Total length, about 4.40 in. (11 1.6 mm.); tail, 1.62 

 in. (41 mm.); foot, .40 in. (10 mm.). 



The range of the Brown Bat includes the whole of Illinois and 

 Wisconsin, and, while there is little doubt that it occurs in more or 

 less numbers throughout both states, actual records are few. It is 

 found in Indiana (Hahn); Missouri (Miller); and is reported from 

 Minnesota by Herrick. The Milwaukee Public Museum collection 

 contains seven specimens of this species from Milwaukee, which are 

 all that are known to have been taken in Wisconsin. For Illinois, 

 Miller records it from Richland and Hancock counties (/. c, p. 97), 

 and Wood reports two specimens from Urbana, Champaign County, — 

 a very meagre list for a species which in 1893 Dr. Harrison Allen con- 

 sidered to be "probably the most common species of any in the United 

 States." 



The Brown Bat, so far as known, differs but little in habits from 

 those of our other species, except that according to Hahn in Indiana 

 it does not have the same partiality for caves, comparatively few 

 being found in such places {I. c, p. 633). They are strictly insectiv- 

 orous and the good they do may be judged from the statement of Dr. 

 R. W. Shufeldt who says: "They drink a good deal and have simply 

 enormous appetites. One specimen, in the course of a single night, 

 consumed 21 June-bugs {Lachnosterna fusca), leaving only a few legs 

 and the hard outside wing-sheaths."* 



While some individuals may migrate southward more or less at the 

 approach of cold weather, a considerable number at least remain in 

 the North and hibernate. Ward records specimens taken in Mil- 

 waukee between December 18 and February 6 (/. c, 1910, p. 181); 

 and Seton mentions a specimen found dormant at Ottawa, Canada, 

 December 3, 1894.! 



* Chapters, Nat. Hist. United States, 1897, p. 440. 



t Life Histories of Northern Animals, II, 1909, p. 1182. 



