Erickson 1934 Perognathus baileyi New River Valley 30 mi. N. of Phoenix, 1650 ft., Maricopa Co., Ariz. Feb. 11, 1934. No. 332 taken on hard packed gravel of mesa; trap set on small mound at mouth of hole; mound of fine soil in contrast to surrounding surface, very old; doubtful if mouse using this particular hole though position in trap suggested this possibility; vegetation creosote and at some distance palo verde and giant cactus. New River Valley. Feb. 12, 1934. Two more individuals secured on coarse hard packed sand at base of granite hill. Traps set near holes in open.