specimens of _S. interrupta_
from Douglas County, Kansas). The degree of each of these kinds of
variation, although considerable, is not extraordinary. That is to
say, the variations are of approximately the same degree as we
previously have ascertained to exist in _Mephitis mephitis_ and in
_Mustela frenata_, two species that are in the same family,
Mustelidae, as _Spilogale_. As a result of our comparisons, we
conclude, first that the four names mentioned at the beginning of this
account all pertain to one species, and second that the three names
_S. gracilis_, _S. p. arizonae_ and _S. ambigua_, and probably also
_S. leucoparia_, were based on individual variations in one
subspecies. _S. gracilis_ has priority and will apply; the other names
are properly to be arranged as synonyms of it, as follows:

1890. _Spilogale gracilis_ Merriam, N. Amer. Fauna, 3:83,
September 11.

1890. _Spilogale leucoparia_ Merriam, N. Amer. Fauna, 4:11,
October 8.

1891. _Spilogale phenax arizonae_ Mearns, Bull. Amer. Mus. Nat.
Hist., 3:256, June 5.

1897. _Spilogale ambigua_ Mearns, Preliminary diagnoses of new
mammals ... from the Mexican boundary line, p. 3, January 12.

Some information in support of the above arrangement, along with some
other observations on _Spilogale_, are as follows: The type specimen
of _Spilogale gracilis_ bears on the original skin-label in the
handwriting of Vernon Bailey, the collector, the statement that the
tail was imperfect. The recorded measurements of 400 for total length
and 142 for length of tail, therefore, are presumed to be subject to
correction. This presumption and the further circumstance that other
specimens from Arizona and New Mexico are as large as specimens of
comparable age and sex that we have examined from Nevada and Utah of
_Spilogale gracilis saxatilis_ Merriam, indicate that _S. g.
saxatilis_ differs less from the allegedly smaller _S. g. gracilis_
than was previously thought. Nevertheless, from north to south (for
example, from northern Nevada to southern Arizona) there is an
increase in extent of white areas at the expense of black areas of the
pelage. As a result, the lateralmost white stripe in _S. g. saxatilis_
averages narrower (and often is wanting) than in _S. g. gracilis_. The
absence, or narrowness, of the lateralmost white stripe seems to be
the principal basis for recognizing _S. g. saxatilis_, just as the
tendency to narrow rostrum i