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 in Coloradan specimens seems to be the principal basis for recognizing _Spilogale gracilis tenuis_ A. H. Howell. Both _S. g. saxatilis_ and _S. g. tenuis_ are "poorly" differentiated from _S. g. gracilis_ and from each other. The holotype of _Spilogale ambigua_ Mearns is slightly smaller than other adult males of comparable age, and the braincase, relative to its width, is slightly deeper than in the average adult male. These variations, nevertheless, are within the range of individual variation, as also are those characterizing the holotype of _Spilogale phenax arizonae_ Mearns. The latter specimen is an adult male, with much inflated mastoidal bullae, nearly straight dorsal profile on the skull, relatively shallow braincase, and only slightly worn teeth.