J Simpson, 1938. 2150 ft, La Estancia, 6 mi. N. Nacori, Sonora. May 19, 1938, continued. and I spent much time before and after putting up the mice cleaning and preparing the deer. Then I left early for the mountains 31 miles to the west at: 2400 ft, Sierra de Mazatan (E. slope), 6 mi. N. Nacori, Sonora. Set 44 mousetraps high on slope among granite- and grass boulders in heavy brush and trees. I don't know the plants here at all; most of the brush is in "dead" state without leaves and brown-black color (a few pitayos and cholla). Returning camp-ward at dusk shot a cottontail rabbit (♀392) and later, after dark, a Starnutated Sauhara Screesh Speckled Owl (♂391) which was in a small tree with a pair of roosting White-winged Doves—the trio within a six-foot-diameter circle. I shot the little owl from about 10 ft. with a half-load .38 which did not kill him outright; when I squeezed his breast to put him out after chasing him through the brush for 20 ft., he dug vigorously at my hands with his talons until dis- patched. Both rabbit and owl at 2250 ft on east slope. May 20, 1938 Caught on the mountain 3 Perognathus penicillatus (♂393, ♀394, ♀395), and six Peromyscus eremicus (♀(20♀+2 jr. no emb. discarded; put up: ♂396, 397, and ♀398. Picked up the skull (399) only of a white-tailed deer on the mountain side; the carcass was post-rotten old and so scattered that age and sex could not be told with certainty. On the way to the trap-line caught a brief sight of a deer in the very dense "jungle" brush or