Conclusions
1. Eutamias and Tamias are distinct genera of chipmunks.
2. The subgenera Eutamias and Neotamias are valid, for, Eutamias sibiricus differs from all the species of the subgenus Neotamias to a greater degree than these species differ from one another.
3. The genera Eutamias and Tamias probably evolved from two distinct lines of sciurids; one line (Eutamias) is represented by the tribe Callosciurini, and the other (Tamias) by the tribe Marmotini.