120 



PROCEEDINGS OF THE NATIONAL MUSEUM 



PLECOTUS I CORVNORHINUS) 



TOWNSEHOII 

 USNM 148550 

 (RIGHT MUZZLE GLAND 

 REMOVED TO EXPOSE FULL 

 EXTENT OF POSTERIOR 

 ELONGATION) 



PLECOTUS (PLECOTUS ) 



AURITUS 

 USNM 16366 



MUZZLE GLAND 



POSTERIOR ELONGATION 



SEPTUM 



NARIAL OPENING 



CORNU 



USNM 102472 



Figure 8. — Muzzles of Plecotus, compared in anterodorsal aspect with the muzzle of 

 Myotis, a generalized vespertilionid. Camera lucida sketches. 



The tragus is relatively long, is broad at the base, and tapers abruptly 

 to a pointed tip. 



Barbastella is a relative of Euderma and Plecotus that lacks the ex- 

 treme auditory specialization characterizing these genera. In this 

 respect, Barbastella must be more primitive than Euderma and Plecotus. 

 On the other hand, in most cranial details Barbastella is similar to 

 Euderma and Plecotus, and in some features such as fragile zygomata, 

 large anterior nares, posterior nares lying far forward, and short tooth 

 rows it has surpassed them in degree of specialization. 



If the assumption is correct that Barbastella is closely related to 

 Euderma and Plecotus, then it follows that most of the cranial char- 

 acters shared by the three genera must have been established before 

 auditory specialization occurred. Further, the Barbastella stock must 



