188 



PROCEEDINGS OF THE NATIONAL MUSEUM 



Figure 24. — Distribution of Plecotus townsendii Cooper (southern section) : \, P.t. australis; 

 2, P. t. ingens; 3, P. t. pallescens. Solid symbols, specimens examined; open symbols, 

 other records; encircled symbols, type localities. Cross-hatching indicates known areas 

 of intergradation between subspecies (between pallescens and ingens in northern Texas, 

 Oklahoma, and Kansas; between pallescens and australis in western Texas, Chihuahua, 

 and Coahuila). 



broad and inflated. Indeed, the whole skull is broad (reflected in 

 zygomatic breadth, breadth of brain case, etc.) in those specimens. 



P. t. australis intergrades with P. t. pallescens. Samples from south- 

 ern Coahuila have the coloration of P. t. australis. Two specimens 

 from near San Buenaventura in central Coahuila resemble P. t. pal- 

 lescens, whereas one from the Chisos Mountains, Texas, is very similar 

 to P. t. australis. Other specimens from the Big Bend region of Texas 

 and Chihuahua are, on the average, sufficiently similar to P. t. palles- 

 cens to be identified as that subspecies, and central and southeastern 

 New Mexican specimens are essentially identical with samples of 

 typical P. t. pallescens (northern and central Arizona). Apparently 



