284 University of California Publications in Zoology. \Vou.6 
clay golor on throat and on sides of neck which is characteristic 
of chrysodcirus; shoulders and upper surface of head slightly 
more ochraceous clay; lateral white stripe tending to be broader 
and somewhat lighter; ventral surface of tail varying from 
ochraceous to tawny ochraceous instead of chestnut; inner lateral 
dark stripe tending to be narrower than the outer (reverse true 
in chrysodeirus). Skulls present no obyious differential char- 
acters. 
Descriptive Remarks.—A majority of the specimens used 
in comparison have already assumed the post-breeding pelage. 
Our series of adults from the Pine Forest Mountains was col- 
lected from June 16 to July 31. There are also at hand a 
number of well-prepared skins of Callospermoplhilus chrysodcirus 
chrysodeirus taken by A. S. Bunnell July 12 to August 2 on 
Mount Shasta. 
The type specimen of trepidus is in the post-breeding pelage 
and is fairly representative of the males of our series. It pre- 
sents the following characters: Cheeks and shoulders ochraceous 
clay, lightest on the cheeks, darkest on the shoulders, where the 
tint approaches tawny ochraceous. Forehead and nose hazel, 
sprinkled with black hairs. Eyelids white. Hairs at the bases 
of ears and along their anterior edges light ochraceous, melting 
insensibly into white toward the posterior part of the pinna. 
Hairs on the inside of the ears light ochraceous for the basal 
two-thirds, having their ends black or very dark brown. The 
three lateral stripes broad; average width (measured from the 
skin): white stripe, 7 mm.; inner black stripe, 8; outer black 
stripe, 10. Ends of both dark stripes obscured. Light stripe 
traceable for some distance in front of and behind the ends of 
the black stripes. Outer black stripe extending about 10 mm. 
farther back than the inner one. White stripe running directly 
into the ochraceous clay of the shoulders, the white hairs of the 
stripe being gradually replaced by light ochraceous hairs and 
finally by darker ochraceous hairs until in the shoulder area it 
is merely indicated. The white of the stripe modified by an 
extremely faint wash of yellow on the tips of the hairs. Region 
between the two inner lateral dark stripes grizzled (ochraceous, 
white, and black). There are more black hairs anteriorly, the 
