KEY TO LAND MAMMALS OF NORTHEASTERN NORTH AMERICA I47 



GKIVERA OF VESPERTILIONIDAB 



Membrane between legs completely furred above Lasiurus, p. 147 



Membrane between legs not completely furred above 



Fur blackish, frosted with white Lasiouycteris, p. 149 



Fur not blackish, frosted with white 



Total length over 100 (4) V e s p e r t i 1 i o , p. 151 



Total length under 100 (4) 



Individual hairs on back with three 



distinct color bauds Pipistrellus, p. 150 



Individual hairs on back with less than 

 three distinct color bands 



Upper front teeth 2 Nycticeins, p. 148 



Upper front teeth 4 Myotis, p. 148 



Genus Lasiurus Gray 

 1831 Lasiurus Gray, Zoological miscellany, no. 1, p. 38 (based on the 

 American hairy-tailed bats). 

 Teeth 32 ; only two front teetb in upper jaw between canines ; dack of mem- 

 brane hehveen legs densely furred y ears short and round. (Lasiurus; Gk.,silk 

 tail) 



The genus Lasiurus is peculiar to America, where it is repre- 

 sented by half a dozen or more species. Two of these occur within 

 our hmits. 



SPECIES OF LASIURUS 



Total length 135 (5^); general color hoary; riui of ear dark... L. cinereus 

 Total length 110 (4:^) ;. general color reddish ; rim of ear light. .. L. borealis 



Lasiurus cinereus (Beauvois) Hoary bat 

 1796 Vespertilio linereus (Obvious misprint for cinereus) Beauvois, 



Catalogue Peale's museum. Philadelphia, p. 14. (Philadelphia Pa.) 

 1864 Lasiurus cinereus H. Allen, Monogr., bats N. Am. p. 21. 

 1897 Lasiurus cinereus Miller, North American fauna. 16 Oct. 1897. no. 

 13, p. 112. 



General color a mixture of light yellowish brown, deep umber brown, and 

 white. Total length, 135 (5^) ; tail vertebrae, 50 (2) ; forearm, 40 (2|). (cine- 

 reus; Lat., gray) 



The hoary bat breeds throughout the forests of the boreal zone of 



North America. In autumn and winter it migrates far to the southward 



of its breeding range. 



Lasiurus borealis (Miiller) Red bat 



1776 Vespertilio borealis Miiller, Natursyst. suppl.-u. regist.-band. 



p. 21. (New York) 

 1897 Lasiurus borealis Miller, North American fauna. 13 Oct. 1897. no. 

 13, p. 105. 



