The specimens upon which the name _artemisiae_ was based came from a narrow tongue of zonally lower country that extends northward from the range of the lighter-colored _gambelii_. As might be expected, topotypes are lighter in color than specimens from the north, west and east. Nevertheless, the type locality is within a geographic area that is occupied principally by a darker race, _artemisiae_, to the north of _gambelii_. The topotypes of _artemisiae_ may be considered to be intermediate between _gambelii_ and the darker, northern race. Thus the name _artemisiae_ becomes available for the mice of the general area in question. The mice of the area immediately to the east of the type locality, in Washington and presumably in British Columbia and Idaho also, are essentially a mixture of the subspecies _gambelii_ and a now mostly extinct and unnamed race that probably resembled _oreas_. Local variations of populations from within this area are extreme but some segregation of color and length of tail has taken place. Mice from mountainous areas resemble _oreas_ while mice from the lowlands resemble _gambelii_, or, more exactly, mice from coniferous forests resemble _oreas_ while mice from other areas resemble _gambelii_. South of the area of racial mixture in northeastern Washington, in the Blue Mountains of southeastern Washington, the deer mice are like _gambelii_ except in slightly darker color. Mice from the Blue Mountains are darker and browner than _gambelii_, not more reddish. There is no indication of adulteration with _oreas_ stock. Since the Blue Mountains are a forested area and are far south of the drift border, we suppose that deer mice existed there through the last glacial period and that their dark color is an adaptation to forest habitat. Mice similar to those of the Blue Mountains have an extensive range in Idaho (Davis 1939: 290). These mice have relatively uniform racial characters and constitute a "good" subspecies. At present the deer mice of northern Washington, southeastern British Columbia, northern Idaho, northeastern Oregon, western Montana and northwestern Wyoming are called _artemisiae_. The mice of this extensive area are, however, of two genetic types: that type with mixed racial characters that lives in northeastern Washington and probably also farther east along the Wisconsin drift border, and that type that occurs farther south in Idaho and seems to constitute a stable subspecies. The separation of these two types may be desirable. Detailed study of the deer mice from the area now assigned to the range of _artemisiae_ may show that the name _subarcticus_ (_Peromyscus texanus subarcticus_ Allen, 1899) is applicable to the southern form. The type with mixed racial characters must be called _artemisiae_. If the two types are eventually separated, the mice from the Blue Mountains of Washington will be referable to the southern form.