W.B. Davis 1935. 422 Cayman, Clark Co., Idaho, June 27. I camped for the night at the Government Canal and on the morning of the 22nd drove up the canal about a mile to a ranch house and hunted for squirrels. They were all C. armatus and were to be found in the vicinity of water, preferring the canal banks or some other embankment in which to burrow. The rancher told me they were a serious menace to the canal banks and had to be kept strictly under control or they would cause breaks in the canal. I saw two C. mollis along this canal in the same peculiar volcanic ash type of soil; one was collected. I shot the other one but it got into the burrow before I could get it. I spent about 4 hours in making up skins and then drove to Blackfoot and camped about 3 miles south of town and set 4 traps in the sandy area around camp in hopes of getting topotypes of Onychomys. The area in which I set was covered with Atriplex, Rabbit Brush and wild sun flowers.