KEY TO LAND MAMMALS OF NORTHEASTERN NORTH AMERICA I47 

 GENERA OF VESPERTILIONIDAE 



Membrane between legs completely furred above Lasiurus, p. 147 



Membrane between legs not completely furred above 



Fur blackisb, frosted with white Lasionycteris, 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 witb three 



distinct color bands Pipistrellus, p. 150 



Individual hairs on back with less than 

 three distinct color bands 



Upper front teeth 2 Nycticeius, p. 148 



Upper front teeth 4 Myotis,p.l48 



Genus Lasiurus Gray 

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

 American hairy-tailed bats). 

 Teeth 32; only two front teeth in upper jaw between canines ; hade of mem- 

 hrane hetiveen legs densely furred ; ears short and round. (Lasiiirus; 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 limits. 



SPECIES OF LASIURUS 



Total length 135 (5^) ; general color hoary; rim 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 (5i) ; tail vertebrae, 50 (2) ; forearm, 40 (2|). (c i n 6 - 

 reus; Lat., gray) 



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

 North America. In autumn and winter it migrates f:ir to the southward 

 of its breeding range. 



Lasiurus borealis (Miiller) Red hat 



1776 Vesperti lio borcwilis Miiller, Nutursyst. supi)l.-u. regi.st.'band. 



p. 21. (New York) 

 1897 Lasiurus borealis Miller, North American fanna. 13 Oct. 1S!)7. no. 

 13, p. 105. 



