lotype of _T. b. aphrastus_ and even greater resemblance
is shown to _T. b. siccovallis_ to which the specimen from Mattomi is
referred.

~Thomomys monticola mazama~ Merriam

This subspecies of the Cascades of Oregon and _Thomomys monticola
nasicus_ of the territory immediately to the east of the Cascades, in
the same state, were originally described (Merriam, Proc. Biol. Soc.
Washington, 11:214 and 216, respectively, July 15, 1897) and redescribed
(Bailey, N. Amer. Fauna, 39:123 and 125, respectively, November 15,
1915) as distinguished from each other by paler color, smaller tympanic
bullae and longer nasals in _T. m. nasicus_. The holotypes do differ in
these respects. The assigned (by Bailey, _loc. cit._) specimens indicate
that the opposite condition obtains with respect to the size of bullae;
that is to say, the bullae are smaller in _T. m. mazama_. In these
referred specimens from Oregon the nasals are actually and relatively
longer in _T. m. nasicus_, which averages paler (less black and more
red). Certain specimens of the two subspecies that are comparable as to
sex, age and season, are indistinguishable in color.

This is the background against which Bailey (_op. cit._:125), contrary
to his statement of geographic ranges (_op. cit._:123, 125) and map
(_op. cit._:fig. 5, p. 23), assigned, in his list of specimens
examined, two specimens ([** Male] ad. 79817 and [** Female] ad. 79818
BS) from Pengra, west of the Cascades, to the subspecies _T. m.
nasicus_. In the specimens from Pengra the bullae are angular as in
referred specimens of _nasicus_ (unlike those of the holotype), the
rostra are intermediate in length between those of the two subspecies
concerned, and the color is light as in _T. m. nasicus_ but can be
matched by that of certain specimens of _T. m. mazama_, for example by
that of No. 79821 BS from Diamond Lake, Oregon. Consequently, on
morphological grounds, the two specimens from Pengra can be assigned to
_T. m. mazama_ almost as well as to _T. m. nasicus_. Having regard for
the geographic relations, we assign them to _T. m. mazama_.

In making this tentative identification we are aware that the
acquisition of more nearly adequate material from Oregon, and critical
study of such material, may bring a subspecific arrangement of the
populations of _Thomomys monticola_ different from the current one.

~Thomomys talpoides bullatus~ Bailey

Bailey (N. Amer. Fauna, 39:101, November 15, 1915) ide