286 University of California Publications in Zoology. (Vou.9 
width (measured from skin): white stripe, 5 mm.; inner black 
stripe, 8; outer black stripe, 7. White of light stripe slightly 
less pure than that of trepidus. Back similar in color to the 
specimen previously deseribed. Others of the series of chryso- 
deirus manifest a distinet tendeney for this region to be darker. 
Grizzled area not encroaching to any extent upon the upper 
surface of the tail. Underparts, except throat and sides of neck, 
soiled white. The dilution of the white is due partly to the 
bases of the hairs being plumbeous for a greater distance than 
in trepidus and partly to a faint wash of ochraceous. <A defi- 
nitely ochraceous area is present in the posterior abdominal 
region along the median line. Throat and sides of neck lght 
ochraceous. Sides slightly darker, there being a somewhat more 
definite suggestion of brown. Fore legs dorsally ochraceous, 
lighter on toes, ventrally light ochraceous; no white. Hind 
leas dorsally like back but with an ochraceous instead of a hazel 
tinge. Lower surface of thighs soiled white. The hairs have 
their bases plumbeous, and their distal portions very light ochra- 
ceous. This color is intensified ‘about the heel. Feet darker 
ochraceous than in frepidus. Ventral surface of tail dark hazel 
close to the body, becoming chestnut distally. Tail dorsally 
similar to frepidus, but the few heht hairs are ochraceous rather 
than light ochraceous. Tail edged with tawny ochraceous. 
A number of our adult specimens of trepidus (nos. 8232, 
8249, and 8258) are in process of molt. As remarked by Allen 
(Bull. Am. Mus. Nat. Hist., III, no. 1, June, 1890, p. 49), “‘the 
new coat with its bright tints appears as patches interspersed 
with the old.’’ The nose seems to be one starting place for the 
molt, the middle of the baek another. 
Sexual variation in color is obvious, the males being instantly 
recognizable through the brighter color of the shoulders and the 
clearer definition of the stripes. In two of the females (nos. 
8227 and 8249) the lateral dark stripes are seal brown instead 
of black. 
A series of 29 juvenals shows that the young of trepidus are 
very similar in color to the adults. Their pelage is of course 
softer and more silky. A number are in the process of molt 
into the bright first winter pelage. In these specimens there 
