1896. _Vespertilio incautus_ J. A. Allen, Bull. Amer. Mus.
Nat. Hist., 8:239, November 21, type from San Antonio, Bexar
Co., Texas.
1928. _Myotis velifer incautus_, Miller and Allen, Bull. U.
S. Nat. Mus., 144:92, May 25.
_Distribution in Tamaulipas._--Probably most of northern
part of state; presently known only from three localities.
The two specimens examined from the Sierra de Tamaulipas were taken in
a mist net in which _Eptesicus fuscus_, _Myotis keenii_, and _Tadarida
brasiliensis_ also were captured. Both are females, one of which was
lactating (June 20). Specimens from San Fernando probably were taken in
houses by natives, who brought the bats to the collectors (Clifton and
Bodley). The maxillary tooth-row and tibia are shorter, breadth across
M3 narrower, and ear slightly longer in Tamaulipan specimens than in
those for which measurements were given by Miller and Allen (1928:95),
but the Tamaulipan specimens do not differ otherwise. The color in
general is slightly more brownish than in Texan _incautus_, but about
as in Oklahoman specimens examined. Three from San Fernando,
Tamaulipas, are darker than others from that state.
The average weight of 12 non-pregnant females from San Fernando was
11.0 (9.5-13) grams. The only male obtained at the same locality
weighed 12 grams.
_Measurements._--Six females from San Fernando afford the
following measurements: 100.0 (95-107); 42.5 (38-46); 10.3
(10-11); 15.3 (14.5-16); length of tibia, 17.4 (16.5-18.9);
length of forearm, 44.8 (43.4-45.7); greatest length of
skull, 16.5 (16.1-16.9); condylobasal length, 15.6
(15.3-15.8); least interorbital constriction, 4.0 (3.9-4.1);
mastoid breadth, 8.3 (8.1-8.6); length of maxillary
tooth-row, 6.5 (6.3-6.7); breadth across M3, 6.5 (6.0-6.9).
_Records of occurrence._--Specimens examined, 15: San
Fernando, 180 ft., 13; Sierra de Tamaulipas, 10 mi. W, 2 mi.
S Piedra, 1200 ft., 2.
Additional record: Soto la Marina (Miller and Allen,
1928:93).
=Myotis keenii auriculus= Baker and Stains