differs in: 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_.
The first two lower premolars are sub-equal in _auriculus_ whereas in
_evotis_ the first lower premolar usually is larger. 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
Nuevo Leon, in both color and degree of slope of forehead, is
intermediate between those from Coahuila and those from Tamaulipas.

A bat from Perote, Veracruz, identified as _Myotis evotis chrysonotus_
(J. A. Allen) [=_M. e. evotis_] by Miller and Allen (U. S. Nat. Mus.,
Bull. 144:118 and 120-121, May 25, 1928) is here assigned to _M. e.
auriculus_. Measurements given by these authors indicate that this bat
has a large skull, which is characteristic of this subspecies. Another
specimen, similarly assigned by these authors and from the San Luis
Mountains in northwestern Chihuahua, seems to be _M. e. evotis_,
although the published measurements (_loc. cit._) show that this bat
tends toward _auriculus_ in size of skull and mandible.

All specimens were taken in mist nets stretched over water. Those from
Coahuila were snared over a concrete water tank situated near the base
of low hills in mixed mesquite and chaparral. In Nuevo Leon, one bat was
netted over a small pond around which grew some low trees in an
intermontane valley in the Sierra Madre Oriental. In Tamaulipas two bats
were caught in a mist net stretched across a narrow, brush-bordered
arroyo in the Sierra de Tamaulipas. One adult male weighed 7.0 grams;
average and extreme weights of 7 adult