1918 | Grinnell: A Synopsis of the Bats of California 289 
(6.0-8.0) ; forearm, 30.5 (29.5-31.5); greatest length of cranium, 
12.8 (12.8-12.9) ; zygomatic breadth, 7.5 (7.3-7.9) ; breadth of brain- 
case, 6.6 (6.46.8) ; interorbital constriction, 2.9 (2.8-3.1). 
MEASUREMENTS IN MILLIMETERS OF TEN ADULTS OF MYOTIS CALIFORNICUS 
PALLIDUS STEPHENS, FROM CALIFORNIA 
ah = S ~ 5 SS ate) 
Mus. . 35 Be 2 2 A se PH =9 
no. Sex = (y= a om om N77 [=a] aha 
10700! fof 81.0 40.0 13.0 6.0 ales) esta 7.9 6.8 3.0 
166567 ret 82.0 42.0 13.0 8.0 30.0 12.8 ed) 6.7 3.1 
17787° rot 77.0 38.0 13.0 7.0 31.5 12.8 7 hes) 6.4 2.9 
19278* Jb 85.0 44.0 14.1 8.0 30.0 12.9 wis 6.5 3.0 
19280" ref 82.0 39.0 14.0 7.0 AOI) ae ae =r 2.8 
10701" 2 75.0 35.0 14.0 60s, y) Sx 13.2 ae 6.3 2.9 
16657" 2 81.0 39.0 14.5 7.0 31.5 13.0 aay 6.4 3.0 
18724* Q 82. 41.0 13.6 7.0 BOLT 12.9 cece 6.4 2.9 
7350" ic) 84.0 40.0 13.9 7.0 31.0 12.5 6.4 3.0 
19279* 2 78.0 38.0 14.0 7.0 30.4 12.5 6.3 2.9 
1From Colorado Kiver, opposite The Needles. 
>From Vallecito, San Diego County. 
* From Lone Pine Creek, 4500 ft., Inyo County. 
‘From La Puerta Valley, San Diego County. 
Synonymy and History.—Myotis californicus pallidus is the pale 
desert form of californicus. It was described by Stephens (1900, 
p. 153), from material secured at Vallecito, San Diego County. 
Distribution—Lower Sonoran Zone on the Colorado and Mohave 
deserts, and north in Owens Valley at least to Lone Pine. (See map, 
text-fig. M.) 
Specimens Examined.—Total number, 15, from the following 
localities in California: Inyo County: Lone Pine Creek, 1; Mesquite 
Valley, 1 (Field Col. Mus.); Panamint Mountains, 1 (Field Col. 
Mus.) ; Kern County: Redrock Canon, 1; San Bernardino County : 
Colorado River, 2; Imperial County: Pilot Knob, 1 (San Diego Soe. 
Nat. Hist.) ; San Diego County: La Puerta Valley, 4; Vallecito, 3; 
Borega Spring, 1 (U.S. Biol. Surv.). 
Natural History.—In the spring of 1910 a party of collectors from 
the Museum of Vertebrate Zoology took four specimens of this bat 
on the Colorado River and were confident that they saw many others. 
J. Grinnell (1914, pp. 265-266) states that the specimens secured 
were all taken at late dusk, considerably later than the bulk appear- 
ance of Pipistrellus hesperus. Instead of flying high against the sky, 
as is the habit of the latter species, M. c. pallidus was almost always 
