AMERICAN BATS OF THE GENERA MYOTIS AND PIZONYX 119 



Type locality. — La Grulla, San Pedro Martir Mountains, Lower 

 California, Mexico. 



Type specimen. — Adult male (skin and skull), No. 10840, Field 

 Museum of Natural History, collected at La Grulla, San Pedro Mar- 

 tir Mountains, Lower California, September 15, 1902, by Edmund 

 Heller. 



Distribution. — San Pedro Martir Mountains, Lower California, 

 Mexico. 



Diagnosis. — Externally resembling Myotis evotis but smaller, fore- 

 arm 34 to 37 mm. instead of 36 to 40 mm., third finger 54 to 58 mm. 

 instead of 62 to 67 mm., and tibia 16.0 to 17 mm. instead of 17 to 

 20 mm. Skull smaller than that of Myotis evotis, the brain case less 

 elevated, noticeably flat-topped, the sagittal crest absent in each of 

 the six specimens examined (nearly always present in adults of 

 M. evotis). Teeth small, the crown area of the upper molars equal 

 to that of the upper molars of M. keenii (crown area of m^ in six 

 specimens, 1.25 to 1.35 by 1.60 to 1.75). 



Color. — The color does not differ appreciably from that of Myotis 

 evotis cKrysonotus. 



Measurements. — For measurements see tables, pages 120 and 121. 



Spedtnens examiTied. — Seven, all from the San Pedro Martir 

 Mountains, Lower California, Mexico (2 skins, 1 skull, F.M., in- 

 cluding type; 4 ale, A. M. N. H.). 



Remarks. — The characters of Myotis lyiilleri appear to be well 

 marked and to indicate the existence, in the San Pedro Martir Moun- 

 tains, of a distinct species related to Myotis evotis and M. keenii. 

 The large conspicuously contrasted black ears and the distinctly 

 fringed interfemoral membrane resemble M. evotis. The general 

 dimensions and small teeth are essentially as in M. keenii. The flat- 

 tened brain case gives the skull a form unlike that of either of the 

 related species and somewhat intermediate between the forms charac- 

 teristic of Myotis keenii and M. suhulatus. The specimens of Myotis 

 milleri differ conspicuously from the type of Myotis niicranyx Nelson 

 and Goldman (collected at Comondu) which has the high brain case 

 and large teeth (m^ 1.45 by 1.95 mm.) characteristic of Myotis evotis. 



