THE FAMILIES AND GENERA OF BATS. 199 



Upper premolars 1-1. 

 Upper incisors 2-2. 



Ears noticeably enlarged. 



Audital bullse as wide as space between them, 



hirplwtis, p. 215. 

 iudital bulla; much wider than space between them, 



Hixtiotus, p. 214. 

 Ears not noticeably enlarged. 



Depth of braincase, including audital bullse, about equal 

 to distance from incisors to posterior root of zygoma, 



Ohiuconyoterls. p. 221. 



Depth of braincase, including audital bullse, much less 



than distance from incisors to posterior root of zygoma. 



Skull noticeably flattened, the occipital depth less 



than one-third greatest length. 



Rostrum broad ; lachrymal region so inflated as 

 to be distinctly visible when skull is viewed 



from below MiiitetlUus, p. 213. 



Rostrum normal ; lachrymal region quite hidden 

 when skull is viewed from below, 



Ti/loiii/dPiis, p. 212. 

 Skull not noticeably flattened, the occipital depth more 

 than one-third greatest length. 



Upper canine with distinct supplemental cusp at 



posterior base of shaft PMletor, p. 213. 



Upper canine without supplemental cusp at pos- 

 terior base of shaft. 



Outer upper incisor large, crowded inward 

 between inner incisor and canine, 



Hesperoptenus, p. 211. 

 Outer upper incisor small, on outer side of 

 inner incisor and widely separated from 

 canine. 



Surface of forearm, tail, and legs thickly 

 sprinkled with small, pointed, horny 

 outgrowths ; upper toothrow strongly 

 concave on inner side anteriorly, 



Rhinopterus, p. 210. 



Surface of forearm, tail, and legs smooth ; 



upper toothrow slightly concave on in-. 



ner side anteriorly. 



Rostrum evenly convex laterally ; 



nares not extending half way to 



interorbital constriction ; palatal 



emargination deeper than broad, 



Eptesicus, p. 207. 

 Rostrum noticeably concave on each 

 side of middle line ; nares extend- 

 ing about half way to interorbital 

 constriction ; palatal emargination 

 broader than deep, 



Vespertilio, p. 209. 



