68 Order CHIROPTERA 



Fur on upper parts of body without bronzy tipped hairs; 

 on under parts pinkish gray; calcar with a small but def- 

 inite keel, fig. 39 ; foot usually 9 mm. long 



Indiana bat, Myotis sodalis 



Skulls 



1. Upper jaw with 1 pair of incisors 2 



Upper jaw with 2 pairs of incisors 3 



2. Upper jaw with 12 teeth . . evening bat, Nycticeius humeralis 

 Upper jaw with 14 teeth Lasiurus spp. 



3. Upper jaw with 14 teeth . big brown bat, Eptesicus fuscus 

 Upper jaw with 16 or more teeth 4 



4. Lower jaw with 18 teeth (2 pairs of premolars) 



eastern pipistrel, Pipistrellus subfiavus 



Lower jaw with 20 t^eth (j pans of premolars) . 5 



5. Upper jaw with 18 teeth (3 pairs of premolars) . . Myotis spp. 

 Upper jaw with 16 teeth (2 pairs of premolars) 6 



6. Rostrum (dorsal view) almost as wide as braincase 



silver-haired bat, Lasionycteris noctivagans 



Rostrum (dorsal view) about half as wide as braincase. . . . 

 southeastern big-eared bat, Corynorhinus rafinesguti 



MYOTIS LUCIFUGUS (LeConte) 

 Little Brown Bat 



Description. — The little brown bat, fig. 52, is of medium 

 size but, like all other bats, it appears to be much larger than 

 it actually is. Although its wingspread may be nearly 10 inches, 

 the animal weighs only a quarter of an ounce, and the head 

 and body are only about 2 inches long. 



The upper parts of the body have olive-brown or yellowish 

 brown fur with a bronzy sheen, and the under parts have gray 

 fur washed with buff. The ears, wings, and tail membrane are 

 dark brown, nearly black, and are almost free of hair. 



Length measurements: head and body 1^-2 inches (45-52 

 mm.) ; tail 1^-2 inches (30-50 mm.) ; over-all 3l4-3}^ inches 

 (82-95 mm.) ; hind foot }i inch (10-11 mm.) ; ear from notch 

 ^ inch (14—16 mm.). 



The skull is small; it has a short rostrum and an over-all 

 length of 14,6-15.1 mm. (about % inch). The braincase is no 

 larger than a dried pea. The incisor teeth are so small as to be 

 hardly visible. Dental formula: I 2/3, C 1/1, Pm 3/3, H 3/3. 



Four closely related species — gray bat, Indiana bat, Keen's 

 bat, and southeastern bat — may occur in the same roostingi 





