290 University of California Publications in Zoology (Vou. 17 
seen low over the bushes of the second bottom, or along shallow washes 
between clumps of mesquite, seldom appearing above the skyline. 
Stephens (1906, p. 266) states that a female little pallid bat cap- 
tured on April 29 contained one small foetus. 
Myotis orinomus Elliot 
La Grulla Brown Bat 
Myotis orinomus Elliot (1903, pp. 228-229). Original description; type 
locality, La Grulla, San Pedro Martir Mountains, Lower California. 
Myotis lucifugus longicrus, J. Grinnell (1908, p. 158), part. San Bernar- 
dino Mountains. 
Myotis orinomus, Grinnell and Swarth (1912, pp. 137-142). Occurrence 
in California. 
Myotis orinomus, J. Grinnell (1918), p. 278). Range. 
Diagnosis —Similar in general characters to Myotis californicus 
californicus, but size slightly larger (total length 79 to 88 milli- 
meters), thumb much longer, color paler (tawny olive), cranium 
flatter and rostrum much broader. 
Description: Head—In general appearance similar to that of 
Myotis californicus californicus but slightly larger. In a series of 
ten dried skins the ear averages in height 11.5 millimeters from notch, 
and the tragus 7.0 millimeters in height. Tragus tall, slender and 
tapering, with tip bluntly rounded. 
Limbs and Membranes——Wing membrane arises from near bases 
of toes. Calear longer than free border of interfemoral membrane, 
and distinctly keeled; in four of ten specimens examined it is lobed 
at tip. 
Pelage—Fur everywhere full and soft, and of a silky texture on 
the back. Most hairs on back average about 6 millimeters in length, 
but scattered among them is a more scanty growth of hairs about 8 
millimeters in length. Wing furred only at extreme base, both above 
and below. Uropatagium scantily haired on basal fifth, both above 
and below; on its ventral surface short hairs are still more sparingly 
scattered over the remaining area. Ear haired on basal fifth of 
posterior surface ; also a very scanty growth of fine short hairs extends 
over entire anterior surface. A few long hairs project from gland- 
ular portions of face, and a row of downward projecting hairs extends 
along upper lip. 
Color.—While a small amount of individual variation in color is 
apparent in the specimens of orinomus at hand, the series as a whole 
bears a very close resemblance in color to a series of Myotis occultus 
from the Colorado River. The hairs are everywhere chaetura black 
at their bases. On the dorsal surface the color of the distal portion 
of the fur varies from light sayal brown to tawny-olive. On the sides 
the darker shade of the back fades gradually into the cartridge buff 
of the lower surface. The membranes are a dark clove brown. 
Skull—kRKasily distinguished from that of any other small Myotis 
by reason of its decidedly flattened rostrum and brain-ease (see pl. 21, 
fig. 26, and pl. 22, fig. 38). This flattening has tended to obliterate 
