south of the Harding County line. This
species appears to have dispersed westward in recent years, and its
future occurrence in the county is likely.

~Gulo gulo luscus~ (Linnaeus, 1758).--The wolverine probably occurred
sparingly in northwestern South Dakota until the time of early
settlement, but we know of no verified records from Harding County or
surrounding areas. A recent report of a specimen taken south of Timber
Lake, Dewey Co., South Dakota (Jones, 1964:283), indicates that it may
again be found in the area.

~Lynx canadensis canadensis~ Kerr, 1792.--We have no reports of this
species in Harding County save that Visher (1914:90) noted that local
residents claimed specimens had "been taken recently in the Cave Hills."
Hoffmann and Pattie (1968:53) reported that the lynx occurs presently in
eastern Montana and we suspect that individuals may occasionally range
into Harding County.

ZOOGEOGRAPHIC COMMENTS

Of the 53 mammals listed in the foregoing accounts, all but one (_Mus
musculus_) are native North American species. These fall into five
rather well-defined faunal groupings as outlined by Hoffmann and Jones
(1970:364-365). A majority (27) can be characterized as "widespread
species." Most of these have broad distributions over much of North
America; a few do not, but are widely enough distributed that it is
impossible to assign them with certainty to a more circumscribed
assemblage. Mammals from northwestern South Dakota that can be
characterized as widespread are: _Myotis leibii_, _Myotis lucifugus_,
_Eptesicus fuscus_, _Lasionycteris noctivagans_, _Lasiurus cinereus_,
_Castor canadensis_, _Peromyscus maniculatus_, _Ondatra zibethicus_,
_Erethizon dorsatum_, _Canis latrans_, _Canis lupus_, _Vulpes vulpes_,
_Ursus americanus_, _Ursus arctos_, _Procyon lotor_, _Mustela frenata_,
_Mustela vison_, _Taxidea taxus_, _Mephitis mephitis_, _Lutra
canadensis_, _Felis concolor_, _Lynx rufus_, _Cervus elaphus_,
_Odocoileus hemionus_, _Odocoileus virginianus_, _Antilocapra
americana_, and _Bison bison_. The above list is composed mainly of
volant or relatively large and mobile mammals, several of which occur
also in Eurasia or range well into the Neotropics.

A few widespread species deserve special comment. Two, the pronghorn and
bison, are typical inhabitants of the interior grasslands of North
America and might be considered steppe species save for the fact that
each has an extensive distribution beyond that r