sitkensis_, _M. o. elymocetes_, _M. o.
yakutatensis_, and _M. o. kadiacensis_. Among the specimens examined of
the latter subspecies were 17 from Izambek Bay, Kodiak Peninsula, on
the mainland opposite Amak Island, the type locality of _amakensis_.
The characters given by Murie (_op. cit._) serve to separate
_amakensis_ from closely related neighboring kinds of meadow mice, but
are of the degree and kind that, in this group of meadow mice, separate
subspecies rather than species. Although actual intergrades are
lacking, the animals from Amak Island are considered to be only
subspecifically distinct and to belong to the _oeconomus_ complex. The
name _Microtus oeconomus amakensis_ is applied to them.

Microtus longicaudus mordax (Merriam)

1891. _Arvicola_ (_Mynomes_) _mordax_ Merriam, N. Amer. Fauna,
5:61, July 30, type from Sawtooth (= Alturas) Lake, 7200 ft., east
base of Sawtooth Mountains, Blaine County, Idaho.

1938. _Microtus longicaudus mordax_, Goldman, Jour. Mamm., 19:491,
November 14.

Dalquest (Univ. Kansas Publ., Mus. Nat. Hist., 2:353, April 9, 1948)
assigned all the meadow mice of the species _Microtus longicaudus_ from
approximately the eastern half of Washington State to _Microtus
longicaudus halli_ Hayman and Holt and, in doing so, excluded the
subspecies _Microtus longicaudus mordax_ from that state. This
assignment of specimens in Washington had the effect of separating the
geographic range of _M. l. mordax_ into two parts. One part was in
south-central British Columbia and the other part was mainly in the
Rocky Mountain region of the United States. Hall and Kelson examined
specimens in the Biological Surveys collection in the U. S. National
Museum in an attempt to determine more precisely the ranges of the
subspecies in southern Canada, Washington, and Idaho.

_Microtus longicaudus angustus_ [= _M. l. halli_] was described by one
of us (Hall, Univ. California Publ. Zool., 37:13, April 10, 1931) as
differing from _mordax_ in narrower braincase, higher skull near the
anterior end of the frontals, darker coloration, and seemingly smaller
size. After examining the material in the U. S. National Museum no
reason is seen at the present time to amend this characterization,
except to add that some specimens of _M. l. mordax_ are as dark as
seasonably comparable specimens of _M. l. halli_.

Examination of specimens of _Microtus longicaudus_ from Washington east
of the Cascade R