1918] Taylor: Revision of the Rodent Genus Aplodontia 465 
ridges. From rainicrt typical columbiana differs in having eranial 
measurements averaging greater, the difference being shown in length 
and width of nasals, length of incisive foramina, zygomatie width, 
mastoid width, and greatest length of mandible. The external auditory 
meatus tends to be of different shape in columbiana, being pinched up 
anteroposteriorly, while in rainier?i the meatus is rounder and tends to 
be flattened dorsoventrally. 
Aplodontia rufa rainieri Merriam 
Mount Rainier Aplodontia 
Aplodontia major rainieri Merriam (1898a), p. 21. 
Haplodontia rufa rainieri, Elliot (1901), p. 112. 
A[plodontia]. r[ufa]. rainieri, Trouessart (1904), p. 348. 
Type—Male adult, skull and skin; no. 90144, U. S. Nat. Mus., 
Biol. Sury. Coll.; Paradise Creek, south side of Mt. Rainier, Wash- 
ington, alt. 5200 ft.; Aug. 6, 1897; collected by Vernon Bailey; orig. 
no. 6122. 
Specimens Examined.—Total number 9, all from Washington ; 
Pieree County—Mt. Rainier, Paradise Creek, 9 (1 skull only). 
Geographic Range.—Known only from yieinity of type locality. 
Cranial Characters —Skull large (see measurements below) ; nasals 
long and comparatively straight sided; posterior two-thirds of outline 
tending to be shghtly convex laterally, but usually with a shght lateral 
embayment far back; rostrum broad, as in columbiana; zygomatic 
arches moderate, proportionally lighter in weight, not so much ex- 
panded near posterior root as in columbiana, flat beneath in vicinity 
of posterior root; temporal ridges tending to remain separated for 
their entire length by several millimeters; caliber of audital tubes 
small; external auditory meatus round or flattened dorsoventrally. 
External Characters—Above, in summer skins, light ochraceous- 
buff, grizzled with blackish, the black hairs often with silvery white 
tips; a tendency observable toward concentration of blackish on middle 
line of back; sides having comparatively few black hairs; underparts 
deep quaker drab to light quaker drab, marked with whitish generally, 
such markings more conspicuous anteriorly on the throat; spot marks 
near light brownish drab; a sparse insprinkling of blackish hairs; a 
faint wash of pinkish buff in some examples. 
Age Variation —There is not so striking an actual decrease in 
width of interorbital constriction with age as is usual in the genus. 
