LEPUS TOWNSENDII.--The white-tailed jack rabbit has probably lived on the Columbian Plateau ever since or even before the time when the Wisconsin ice bordered the plateau on the north. LEPUS AMERICANUS.--Snowshoe rabbits were probably spread over forested parts of Washington in pre-Wisconsin time. A coastal race, _washingtonii_, was probably distinct from the remainder of the species at an early time. It, and its kindred races _klamathensis_ and _tahoensis_, are very different from races derived later from the Rocky Mountain Fauna. From this it is deduced that _washingtonii_ was a member of the Pacific Coastal Fauna before the advance of the last continental glaciers. The snowshoe rabbits now found in the Cascade Mountains of Washington are racially distinct from populations occurring to the north and east, but are more closely related to the northern and eastern rabbits than they are to _washingtonii_. This race, _cascadensis_, probably lived in the area north of the state of Washington in pre-Wisconsin interglacial time. The snowshoe rabbit of northeastern Washington was probably a race having an extensive range in the Rocky Mountains from which _pineus_ in the Blue Mountains developed. The descent of the Vashon-Wisconsin glaciers found _washingtonii_ restricted to western Oregon. It might have persisted also in southwestern Washington but, had this been the case, we would expect a broader zone of intergradation between _washingtonii_ and _cascadensis_ than actually exists. The glaciers forced _cascadensis_ southward into the Cascades of southern Washington. The difference between _washingtonii_ and _cascadensis_ and the narrow zone of intergradation between them, indicate that the two races were not in contact in pre-Vashon Time. The presence in the Cascades of Oregon of a race related to _washingtonii_ rather than _cascadensis_ also supports this view. The snowshoe rabbits of northeastern Washington were probably eliminated from areas where the ice was in place. The effect of the glaciers in nearby areas was probably less on snowshoe rabbits than upon other species. Following the retreat of the glaciers, _washingtonii_ reinvaded western Washington and spread northward through the lowlands to the Fraser River. In the Cascades, _cascadensis_ moved even farther north. _L. a. pineus_ of the Rocky Mountain Fauna invaded northeastern Washington from adjacent areas to the south. Another race, _columbiensis_, spread from the interior valleys of British Columbia to the western part of northeastern Washington in probably relatively recent times. The post-Wisconsin history of the distribution of this race is uncertain.