456 University of California Publications in Zoology — (Vou. 17 
Mts., head of Grizzly Creek, 3. Humboldt County—‘‘ Northwest California’’ 
| Hoopa Valley], 2 (no skulls); Rio Dell, 1. 
Geographic Range.—Neighborhood of the Columbia River, in west- 
ern Oregon, interiorly on the Pacific side of the Cascades; thence 
southward in a belt of unknown width to Mount Mazama in southern 
Oregon and the Siskiyou-Trinity district im northern California ; 
northward to Puget Sound and the Chilliwack-Sumas region in south- 
western British Columbia. Altitudinal range, from sea level in the 
Puget Sound district to 6,500 feet in the Siskiyou-Trinity Mountains 
of northern California; zonal range, Transition and Canadian. 
Cranial Characters —Skulls moderate (see measurements below), 
nasals variable in outline, broad anteriorly, but usually much nar- 
rowed at their posterior ends; rostrum short; audital tubes in typical 
material tending to be of greater caliber than in other forms of the 
genus, about as in californica (see Remarks, below). 
External Characters—Above, in specimens taken at all seasons, 
light ochraceous-buff (Ridgway, Color Standards and Color Nomen- 
clature, 1912), in some specimens grading anteriorly into light buff, 
vinaceous-cinnamon or even occasionally approaching tawny; some 
with a distinetly grayish, others a distinctly brownish cast of color- 
ation; some examples paler anteriorly and grayer posteriorly, with 
deepest coloration in middle region of body; grizzled with more or 
fewer blackish hairs; white spot at base of ear; some silvery-white 
hairs insprinkled, particularly posteriorly. Below, grayish, with the 
faintest possible wash of brownish of a hue near pinkish buff, or 
brownish, with a conspicuous wash of vinaceous-cinnamon or light 
vinaceous-cinnamon, and with seattered black hairs insprinkled ; prae- 
tically all hues between these are observable; drab-gray basal color- 
ation showing through to a greater or less degree; spot-marks about 
mammae in spring and fall females seal brown or paler in coloration. 
Molt and Seasonal Change—That Aplodontia rufa rufa molts 
once, that the pelage renewal takes place during the late summer and 
the fall, and that a term of from two to three months is required for 
the completion of the molt, is suggested by the following facts: 
Specimens taken May 17, June 5, 22, 23, and July 22 and 23, and 
even two exceptional specimens taken August 26 and September 13, 
are much worn but show no sign of molt. On the other hand, molt 
has already begun in other specimens of rufa taken on June 23 and 
24, and pelage renewal is going on in practically all specimens taken 
during August, September and October. Examples secured Septem- 
