Oct. 29 Pitahaya, 40 pm. 5E Empalme, 100 feet, Sonora. Hunted just south of camp along the margin of the slough. Mocking birds are very numerous; migrant flocks of sparrows, mainly Chondestes, Zonotrichia, and Spizella breweri, occur sporadically. Oct. 30. Hunted around the west end of the slough. New species seen today were Heliodytes, Barabutes, Passerculus, all collected, and Dendroica townsendi; Anser albifrons, 9 yesterday, 15 today, was observed on several occasions flying along the slough. Oct. 31 Stayed in camp, hunting only briefly nearby, mainly to catch up on note-writing. Judging by Van Rossem (1945), the local hummers, seemingly made up mainly of females and young birds, should be Calypte costae. A young male collected today proved to be of this species. It is possible that there are adult males present, but that they do not pass into the nuptial plumage as directly as does C. anna. In the past four days, Leopold's and Russell's concentration on the ducks have yielded a list of 8 species, most all of them collected. A few large groups of ducks apparently remain on the slough during the day, but a larger total number leaves early in the morning, flying