Quack 1948 Journal 73 May 20 6 mi. E of San Antonio, Baja California. bags we had available at the time. I have noticed that so far it seems as though we have found bats only in caves and mines that are quite open or else ventilated in some way so that a draft can be felt. None of the female 'Leptonycteris' that I put up had embryos. I noticed that they came in two shades of brown, varying from reddish to dark grey. The hill in which we found the mine was covered with Palo Blanco trees with a few Pitaya dulce and Prickly Pear cactuses growing underneath the trees. May 21 6 mi. E.S.E. San Antonio, 1200 ft. Baja California Went hunting last night and obtained two Elf Owls between 8:30 and 9:00 P.M. They were located by their calling from the branches of bare trees along the road. A very faint eyesline was detected in one which was a very light yellow. They seemed to be associated in pairs, for each time I shot I would notice one flying from a nearby tree. Dr. Benson saw one peering out from a small hole in a Cardon but did not obtain it. I put up one (#235), Dr. Benson the other one. The Elf Owls which were seen were perched on the lower branches of