1918] Taylor: Revision of the Rodent Genus Aplodontia 473 
CRANIAL MEASUREMENTS OF Aplodontia humboldtiana (15 SKULLS) 
Average Mean Maximum Minimum 
TEYYSVU Ea TTS lO ae et pee eee eee .- 58.8 58.7 55.0 
Length of nasals (11 skulls) 24.5 23.8 21.9 
Width of nasals —........... 11.2 11.2 10.0 
Length of audital tube (12 18.4 18.0 16.5 
Length of incisive foramen .- 5.9 6.5 4.8 
Pi AEROVSTED ING, ASAI NE, oe eon 53.8 53.2 57.9 48.6 
Greatest width of interpterygoid fossa ........... 5.5 5.7 6.7 4.8 
Mastoid width of cranium .......00.0......... eee 51.7 57.4 46.0 
Alveolar length superior cheek teeth ...... =. 18:8 18.6 19.7 17.6 
Distance between infraorbital foramina ............ 16.4 ileal 18.9 15.4 
Mandible, transversely across angular process ... 22.2 21.6 23.9 19.4 
Mamaiblessoreatest Lemp th) <2... oo. 2 ccccsccsteccecescereveorns 48.1 48.1 50.7 45.6 
EXTERNAL MEASUREMENTS OF Aplodontia humboldtiana (15 SKINs) 
Average Mean Maximum Minimum 
AN aysCell evakag a, oe ree eee reer 346 333 367 300 
Ti OO teases see anecen eee 56 56 63 50 
Remarks.—A plodontia rufa hwmboldtiana is larger and less richly 
colored than Aplodontia rufa pacifica of the coast region of Oregon 
(see p. 469). Humboldtiana is similar in coloration to A. r. rufa, of 
the Trinity-Siskiyou Mountain region to the eastward, but darker, a 
paler hue of the brown series of colors being interspersed with the 
black hairs. The Humboldt aplodontia is not so black as is A. r. nigra, 
its nearest neighbor on the south, although in certain cranial charac- 
ters, notably width of nasals, length of incisive foramen, zygomatic 
width, greatest width of interpterygoid fossa, and mastoid width, it 
is closer to nigra than to any other one of its neighbors. 
Specimens from Sam Lane’s Ranch, twelve miles north of Hoopa 
and three miles southwest of Weitzpek, on the divide between the 
Klamath and Trinity rivers (nos. 97290, 97291, 98475, U.S. Nat. Mus., 
Biol. Surv. Coll.), here referred to humboldtiana, show intergradation 
in the direction of A. r. rufa. 
Aplodontia rufa californica (Peters) 
Sierra Aplodontia 
Aplodontia leporina (part), Audubon and Bachman (1854), pp. 99-103. 
Marmot, Mammoth Mole, Calif. Acad. Nat. Sci. (1855), p. 71. 
H{aplodon]. leporinus var. Californicus Peters (1865), pp. 177-179. 
H{aploodon]. californicus, Lilljeborg (1866), p. 41. 
Haplodon rufus, Coues (1877b), p. 557. 
Aplodontia major Merriam (1886), p. 316. 
H{aplodon]. major, Townsend (1887), p. 174, footnote. 
H{aplodontia]. major, Elliot (1899), p. 251. 
Haplodontia rufa californica, Elliot (1901), p. 112. 
Aplodontia rufa californica, Trouessart (1904), p. 348. 
Aplodontia californica, Grinnell (1913), p. 344. 
