462 Umversity of Califorma Publications in Zoology — (Vou. 17 
Molt and Seasonal Change—The only months represented by 
available specimens of olympica are July and August. In the series 
at hand the molt begins about the middle of July, and is not com- 
pleted till September at the earliest. One example (no. 67615, 9, 
U.S. Nat. Mus., Biol. Surv. Coll.), secured August 17, is exceptional 
in that even at that late date it shows no sign of molt. On the basis 
of specimens at hand the winter coat is a little browner than the 
summer pelage. 
Figs. I-K. Side view of crania of Aplodontia rufa olympica, to illustrate 
variation in development of postorbital process of the jugal. XxX 1. Fig. I, no. 
66229, Biol. Sury. Coll.; fig. J, no. 6314, Field Mus. Nat. Hist.; fig. K, no. 89549, 
Biol. Sury. Coll. 
Remarks.—Aplodontia rufa olympica is a feebly marked race of 
the rufa series occurring in the Olympic Mountain district of Wash- 
ington, and grading insensibly into rufa to the east and southeast. 
Additional material from scattered localities in western and north- 
western Washington may demonstrate so great a degree of variability 
as to make inadvisable the separate recognition of the Olympic Moun- 
tain form. The postorbital process on the jugal, the most important 
