Figure 8. — Unlike the upper incisors of other southeastern 

 bats (B), the upper incisors of the Brazilian free-tailed bat 

 {Tadarida brasiliensis) converge at the tips (A). 



Key to Bat Skulls 



1. a. Upper incisors obviously converge at tips (i.e., 

 much closer together at tips than at base, Fig. 8a) — 

 Brazilian free-tailed bat ( Tadarida brasiliensis) 



b. Upper incisors wider at tip than base, equidistant at 

 tip and base, or tips slightly converging (Fig. 8b) — 2 



2. a. There are nine teeth in upper quadrant (one side of 

 upper jaw) — Myotis spp. 



b. Fewer than nine teeth in upper quadrant — 3 



3. a. Eight teeth in upper quadrant — 4 



b. Fewer than eight teeth in upper quadrant — 7 



4. a. Upper incisor bifid (two-cusped) — Rafinesque's 

 big-eared bat {Corynorhinus rafinesquii) 



b. Upper incisor unicuspid — 5 



5. a. Greatest length of skull more than 13.5 mm; 

 rostrum flat with two concavities on dorsal surface — 

 silver-haired bat (Lasionycteris noctivagans) 



b. Rostrum sloped with no concavities on dorsal 

 surface — 6 



6. a. Rostrum strongly sloped; greatest length of skull 

 more than 13 mm — Townsend's big-eared bat 

 {Corynorhinus townsendii) 



b. Rostrum gendy sloped; greatest length of skull less 

 than 13.5 mm — eastern pipistrelle {Pipistrellus 

 subflavus) 



7. a. Seven teeth in upper quadrant — 8 

 b. Six teeth in upper quadrant — 1 1 



8. a. Two upper incisors (one large, one minute) — big 

 brown bat {Eptesicus fuscus) 



b. One upper incisor — 9 



9. a. Greatest skull length more than 15.5 mm — hoary 

 bat {Lasiurus cinereus) 



b. Greatest skull length less than 15.5 mm — 10 



