THE MIGEATION OF BATS. 87 



This negative evidence of the bat's absence from its breeding-range in the late fall 

 and winter, coupled with the foregoing positive records of its occurrence at this season 

 in many places far to the south, may be fairly regarded as conclusive evidence of 

 migration. 



The Hoary Bat (Atalapha cinerea) is not the only species concerning which there is 

 evidence of migration. The Silver-haired Bat (Vesperiigo noctivagans) may be classed in the 

 same category. A granite lighthouse stands upon Mount Desert Rock, a lonely, barren 

 dot in the ocean off the coast of Maine, twenty miles S. S. E. of Mount Desert Island, fifteen 

 miles from the nearest island, and thirty miles from the mainland. The rock is so small 

 and bleak that it is not inhabited by bats. Still, as I have been informed by the keeper of 

 the lighthouse, Mr. Thomas Milan, a few small dark-colored bats visit the i:)lace during 

 the migrations, every spring and fall. In order to identify the species, Mr. Milan, at my 

 request, was kind enough to send me several specimens procured about October 1st, 1885. 

 They proved to be the Silver-haired Bat {Vesperugo noctivagans). 



Mr. W. T. Davis informs me that a specimen of this species was captured in an unfur- 

 nished house at Staten Island, New York, about the end of October, 1885. As the bat is 

 known to breed in southern New York, this record, taken alone, would not amount to 

 much, but in connection with others it is of some significance. On November 12th, 1885, 

 Dr. A. K. Fisher shot an adult female at Washington, D.C. The specimen is now in my 

 collection (No. 1395.) The species has been taken even in the Bermudas, where, according 

 to Mr. J. Matthew Jones, an individual was captured October 8th, 1850. The power of 

 flight in the Silver-haired Bat is far inierior to that of the Hoary Bat, which fact must 

 have an appreciable efiect on the extent of its migrations. 



It is not improbable that the Red Bat {Atalapha Noveboracensk) also is a migrant, but 

 since it breeds in the south as well as the north, and since, like other bats, it is nocturnal 

 in habits, its movements are exceedingly difficult to follow. 



