Quast 1948 Macrotus californicus 5 May 23 Buena Vista, 25±ft, 23°38'N, 109°41'W, Baja California net over the cave entrance and then capturing the specimens by hand as they flew against the net. Those caught were put outside the net excepting those saved. An estimated 50 remained in the back of the cave when we left. The Macrotus were noticed to cluster very close together in a tight mass when hanging after being frightened. They bite quite severely at times, being painful if a sensitive spot in the hand is grabbed. When removed from the sack at camp many were noticed to be dead. Many of the individuals were bloody from being bitten by their neighbors, some dead individuals still having their jaws clamped into others with such force that two bats would raise when one was lifted. May 24 Las Cuevas, 23°34'N, 109°39'W, Baja California About ten seen in first cave visited and several hundred in each of the two following caves. (See journal May 24). June 2 6 mi N San Jose del Cabo, 250±ft, Baja California Approx, 20 seen in small cave in small cliff face 100 yards south of camp. The cave is about 20 feet deep and of a size just large enough to accomo- date Dr. Benson on his hands and knees. The bats seemed to be divided evenly between both sexes. None taken.