1918 | Taylor: Revision of the Rodent Genus Aplodontia 483 
across the lower side of the ramus and connected with the inner promi- 
nence of the angle. 
Seasonal Change——Molt begins the last of July or the first of 
August. Specimens taken September 17 and November 9 have the 
process about completed, and one secured November 12 has entirely 
finished molting. More black hairs are sprinkled into the winter 
pelage, and the hair is somewhat longer and thicker. The spot marks 
about the mammae in the females are much less conspicuous in winter 
than in summer. 
CRANIAL MEASUREMENTS OF Aplodontia rufa phaea (11 SKULLS) 
Average Mean Maximum Minimum 
IBS AS Ma PLO OG ip sea cece ec Sos ecto cost ezcceesececeece -- 59.6 54.8 58.6 51.1 
Length of nasals (4 skulls) ... 21.5 22.0 23.7 20.3 
Width) of masals) -4.2-..-<--..2.2.-: 9.6 9.5 10.3 8.7 
Length of audital tube (9 skulls) 16.3 16.4 17.2 15.6 
Length of incisive foramen 6.2 6.1 7.6 4.5 
Zygomatie width .................----- 50.3 49.5 53.0 46.0 
Greatest width of interpterygoid fo : - 43 4.2 4.7 3.8 
Mastoid width-of cramium ..-........-2--<-:--cc-cecscse0--- 47.2 46.4 51.0 41.9 
Alveolar length superior cheek teeth 0... 18.4 18.5 19.2 iW) 
Distance between infraorbital foramina ney el De 15.3 16.5 14.1 
Mandible, transversely across angular Pee pee 2186 21.7 22.8 20.7 
Mandible, PTeATe Salen Oi Ne ecekssexsevecsce tees ance renee 43.1 43.4 45.1 eeley/ 
EXTERNAL MEASUREMENTS OF Aplodontia rufa phaea (13 SKINS) 
Average Mean Maximum Minimum 
308 312 344 280 
52 52 57 48 
Total length .. 
Hind foot .... 
Remarks.—Aplodontia rufa phaea is the smallest subspecies in the 
genus. It is also the palest of the coastal forms of Aplodontia (pa- 
ctfica, humboldtiana, nigra, phaea) occurring in Oregon and California. 
Cranially its closest affinities seem to be with Aplodontia rufa nigra. 
In spite of the geographical isolation of the Marin County form, 
it is very similar, in general coloration, to some examples of rufa; nor 
are its cranial characters sufficiently distinctive to warrant its recog- 
nition as of more than subspecifie rank. 
