294 University of California Publications in Zoology  [Vou.17 
Nevada County, is somewhat different in coloration, being paler and 
erayer throughout, with ears and membranes blackish mouse gray. 
Skull.—About 16 millimeters in length; slender and delicately 
built (pl. 21, fig. 34, and pl. 22, fig. 46). Posterior margin of brain- 
case rounded and occipital ridges but faintly defined. The only other 
Californian species of this genus which have skulls similar in length 
to that of evotis are Myotis velifer and M. thysanodes. Upon com- 
parison it will be noted that in velifer the rostrum is heavily built, 
the sagittal crest is distinct, and the posterior margin of the brain- 
case is truncate, whereas in evotis the rostrum is lightly built, the 
ridges are indistinct and the posterior margin of the brain-case is 
rounded. The differences between the skulls of evotis and thysanodes 
are not so tangible, and it is somewhat difficult to properly allocate 
skulls of young individuals of these two species. But in adults 
the brain-case of thysanodes is much more inflated than that of evotis, 
the breadth of the brain-case in thysanodes is relatively greater, and 
the rostrum is heavier. 
Mcasurements——Measurements in millimeters of an adult female 
(with one embryo) taken near Pasadena, May 29, 1904, are as fol- 
lows: total length, 93.0; tail vertebrae, 43.0; tibia, 16.6; foot, 7.0; 
forearm, 37.5; greatest length of cranium, 16.2; zygomatic breadth, 
9.1; breadth of brain-case, 7.5; interorbital constriction, 3.7. 
Synonymy and History.—Myotis evotis was described by H. Allen 
(1864, pp. 48-50) under the name Vespertilio evotis. No type 
locality was designated by that author, but Miller (1897), p. 78) 
fixes Monterey, California, as the type locality, selecting one of the 
localities given by H. Allen. In his monograph of 1894 (pp. 89-91), 
Allen regards evotis as a race of Vespertilio albescens, and lists under 
the same name a specimen of Myotis thysanodes (see Miller, 1897), 
p. 80). 
Distribution.—Given by Miller (1912, p. 59) as the Austral and 
Transition zones from the Pacific coast to the eastern edge of the 
Rocky Mountains; south to Vera Cruz, Mexico. In California the 
range of Myotis evotis is not well defined as far as shown by the facts 
yet available. It seems to comprise the Upper Sonoran and Transi- 
tion zones from the Mexican line northwards as far as Mount Shasta; 
west to the eastern boundary of Mendocino County, and east to Inde- 
pendence Lake, Nevada County, and the Inyo Mountains, in Inyo 
County. (See map, text-fig. N.) 
Specimens Examined.—Total number, 22, from the following 
localities in California: San Diego County: Dulzura, 2 (Amer. Mus. 
Nat. Hist., 1; Acad. Nat. Sei. Phila., 1) ; Witch Creek, 2 (San Diego 
Soe. Nat. Hist.) ; Twin Oaks, 1 (U.S. Biol. Surv.) ; San Bernardino 
County: San Bernardino, 1 (San Diego Soe. Nat. Hist.) ; Los Angeles 
County: near Pasadena, 2; North Fork San Gabriel River, 1 (Ll. A. 
