30. and seems to bring out the principle that "habitat predetermines the type of inhabitant." At our morning's Camp the Lemadon area was isolated seemingly by one factor, that of vegetation. The ideal habitat for these squirrels seems to be the combination of powdery white-clay soil, fairly steep terrain and a certain kind of thorny Atriplex bush, that might form vantage points + perhaps some food. Where the Atriplex bushes occur, the individuals are rather widely spaced (perhaps averaging 3'); this gives them the "Lemadons" plenty of room for their large low & compliy mounds. The first colony mentioned seemed circumscribed by the presence of the Atriplex. The soil, however, was the same for miles around the inhabited area. In one occasion near Reynolds Cr. I noticed the some Atriplex bush in abundance yet the soil was hard + gravelly; thus no "Lemadons" were present. A little farther beyond the soil changed (Atriplex present) to the required clay + many of their workings were present but none were seen (squirrels), perhaps because of its been late in the afternoon. They probably can stand.