Rollin H. Baker

“ Ears averaging shorter; color darker and richer; ears paler and contrasting less, in color, with pelage; skull larger in all measurements taken except that of least interorbital constriction; forehead, when viewed laterally, rising more abruptly, because frontal region is more inflated; teeth larger.
Remarks.—Myotis evotis auriculus, although no larger externally than M. e. evotis, has a larger skull, which in lateral view has a more abruptly rising forehead. The teeth, especially the first upper premolars, of auriculus are noticeably larger than those of evotis. ”

“ Long-eared bats obtained by field parties from the University of Kansas in the Mexican states of Coahuila, Nuevo León, and Tamaulipas, are found to belong to the species, Myotis evotis, but are not referable to any named subspecies. They are named and described as follows:
Myotis evotis auriculus new subspecies
Type.—Female, adult, skin and skull; No. 55110, Univ. Kansas Mus. Nat. Hist.; 10 mi. W and 2 mi. S Piedra, 1200 ft., Sierra de Tamaulipas, Tamaulipas ”

“ The mandible, in relation to the greatest length of the skull, is longer in auriculus (ratio, 71-74) than in evotis (ratio, 67-71) .
Coahuilan specimens, although assigned to auriculus, are slightly paler (upper parts (16) Ochraceous-Tawny; underparts (e) Light Buff) and have less abruptly rising foreheads than do the bats from Tamaulipas. In these features, the Coahuilan animals are somewhat intermediate between typical auriculus and evotis. The bat from [Pg 84] Nuevo León, in both color and degree of slope of forehead, is intermediate between those from Coahuila and those from Tamaulipas. ”