_Diagnosis._--Size small (see measurements). Color pale, upper parts being near (16"_j_) Snuff Brown (capitalized color terms are of Ridgeway, Color Standards and Color Nomenclature, Washington, D. C, 1912); underparts dull Pinkish Buff to nearly white in some specimens; ears and flight membranes near (16"_l_) Olive Brown; skull small. _Comparisons._--From _Myotis velifer incautus_ (J. A. Allen), _Myotis velifer brevis_ differs in: Size smaller; color slightly darker; skull smaller. From _Myotis velifer peninsularis_ Miller, _M. v. brevis_ differs in: Size larger; color darker; skull larger. From _Myotis velifer velifer_ (J. A. Allen), _M. v. brevis_ differs in; Size smaller; pelage paler, with less extensive basal dark portion; skull smaller. TABLE 1.--MEASUREMENTS, IN MILLIMETERS, OF MYOTIS VELIFER ============================================================================ | Sex | Number | Average | Range | | averaged | | ----------------------+-----------+----------+---------+-------------------- _M. v. velifer_, 4 km. E Las Vigas, 8,500 ft., Veracruz, Mexico. ----------------------+-----------+----------+---------+-------------------- Total length | [Male] | 15 | 97.1 | 92.0-101.0 " " | [Female] | 9 | 99.0 | 93.0-103.0 Length of forearm | [Male] | 27 | 44.1 | 42.1-46.0 " " " | [Female] | 18 | 44.7 | 43.3-46.1 Condylobasal length | [Male] | 15 | 15.9 | 15.4-16.2 " " | [Female] | 9 | 16.0 | 15.7-16.4 Interorbital breadth | [Male] | 15 | 4.2 | 3.9-4.2 " " | [Female] | 9 | 4.1 | 3.9-4.3 Mastoid breadth | [Male] | 15 | 8.4 | 8.2-8.5 " " | [Female] | 9 | 8.4 | 8.2-8.6 Zygomatic breadth | [Male] | 15 | 10.7 | 10.4-10.9 " " | [Female] | 9 | 10.7 | 10.4-11.2 ----------------------+-----------+----------+---------+-------------------- _M. v. incautus_, 4 mi. E Sherman, Major Co., Oklahoma. ----------------------+-----------+----------+---------+-------------------- Total length | [Male] | 11 | 101.5 | 97.0-107.0 Length of forearm | [Male] | 9 | 45.4 | 44.6-47.3 Condylobasal length | [Male] | 11 | 16.4 | 15.9-16.7 Interorbital breadth | [Male] | 11 | 4.2 | 4.0-4.5 Mastoid breadth | [Male] | 11 | 8.8 | 8.5-9.1 Zygomatic breadth | [Male] | 11 | 10.9 | 10.5-11.3 ----------------------+-----------+----------+---------+-------------------- _M. v. brevis_, Riverside Mtns., 35 mi. N Blythe, Riverside Co., California. ----------------------+-----------+----------+---------+--------------------