_Comparisons._--From _Leptonycteris nivalis nivalis_ (specimens from Veracruz, Oaxaca, Distrito Federal, Hidalgo, Jalisco, and Sonora), _L. n. longala_ differs as follows: color paler, more whitish and less brownish; third finger longer (_longala_ from Coahuila averaging 111.3 mm.; _nivalis_ from Sonora averaging 91.0, from Jalisco 96.4, from Hidalgo 98.0, from Veracruz 100.0, from Distrito Federal 100.2, and from Oaxaca 98.6); skull larger, breadth of cranium greater (_longala_ from Coahuila averaging 10.7 mm.; _nivalis_ from Sonora 9.8, from Jalisco 9.8, from Hidalgo 9.6, from Veracruz 9.9, from Distrito Federal 9.9, and from Oaxaca 9.8); mastoidal breadth greater (_longala_ from Coahuila averaging 11.6 mm.; _nivalis_ from Sonora 10.5, from Jalisco 10.8, from Hidalgo 10.6, from Veracruz 10.9, from Distrito Federal 10.8, and from Oaxaca 10.7); skull higher (_longala_ from Coahuila averaging 10.0 mm.; _nivalis_ from Sonora 9.3, from Jalisco 9.2, from Hidalgo 9.2, from Veracruz 9.3, from Distrito Federal 9.3, and from Oaxaca 9.1). The average of each dimension of _longala_ listed above exceeds the maximum of the corresponding dimension in _nivalis_. _Remarks._--_Leptonycteris nivalis longala_ inhabits the northeastern end of the Mexican Plateau. Bats from Brewster County, Texas, referred to _longala_, average slightly larger in all measurements taken than do specimens from southern Coahuila. Specimens from Cerro Potosi, Municipio de Galeana, Nuevo Leon, also are referred to _longala_ on the basis of the length of their third fingers. Like the specimens from Texas, these bats possess longer forearms, on the average, than do bats from Coahuila.