66 Order CHIROPTERA 



ings may be objectionable because the droppings that accumulate 

 produce an odor that generally is regarded as unpleasant. 



KEY TO SPECIES 



Whole Animals 



Bats are rather difficult to identify; often a fresh specimen can 

 be more readily identified than a study skin or preserved speci- 

 men. The following key to the whole animals is designed for liv- 

 ing or freshly killed bats and for study skins in which detailed meas- 

 urements accomoany the skin and skull. In each instance, the ear 

 length, forearm length, or foot length is that of a fresh specimen. 



1. Ear more than 30 mm. (H/y in.) long; glandular outgrowth 



or lump on side of muzzle 



southeastern big-eared bat, Corynorhinus rafinrsguii 



Ear less than 23 mm. [p/% in.) long; no prominent lump on 

 side of muzzle 2 



2. Upper surface of tail membrane completely furred, fig. 56 ; 



under side of wing with a patch of fur on distal part of - 



forearm 3 



Upper surface of tail membrane entirely bare. fig. 55. or at 

 least posterior third bare; under side of wing naked . 4 



3. Fur brick or rusty red, dusted with white; forearm less 



than 44 mm. (1^4 i n -) l° n g; over-all length less than 



115 mm. (4j ^ in.) red bat, Lasiurus boreal is 



Fur a mixture of bright buff, yellows, and deep amber, 

 heavily frosted w'th white in waves over the back; fore- 

 arm more than 44 mm. long: over-all length more than 

 130 mm. (5 in.) hoary bat, Lasiurus cinereus 



4. Fur black or blackish brown, frosted with white; premolars 



on each side of jaws 2 above, 3 below 



silver-haired bat, Lasionycteris noctivagans 



Fur neither black nor frosted with white; premolars on 

 each side of jaw not 2 above, 3 below 5 



5. Over-all length usually 105 mm. (41 s in.) or more; fore- 



arm length usually 45 mm. (1$4 in.) or more 



big brown bat, Eptesuus fuscus 



Over-all length usually less than 105 mm.; forearm length 

 less than 45 mm. . . 6 



6. Fur on back with hairs not darkened at bases; forearm 



length usually 40 mm. (about l 1 _• in.) or more 



gray bat, My otis grisescens 



Fur on back with hairs darkened at bases; forearm length 

 usually less than 40 mm 7 



7. Fur on back with hairs distinctly tricolored ; forearm and 



fingers red; upper jaw with 2 pairs of premolars 



eastern pipistrel, Pipistrelltu subflavus 



Fur on back with hairs not distinctly tricolored; forearm 



