Quack 1948 Journal 146 June 30 Santa Rosalia, 10° ft., Baja California (Minaka Zonta) lightening to the east over the Gulf at dark. Min- imim temperature 74°. Visited a mine this afternoon lying west of this town in the same arroyo at a distance of about 2 miles by road from the center of town. The name of the abandoned mine is “Mine La Zonta” and it is composed of a single horizontal tunnel of about 4½ by 5½ feet and 100 to 150 yards in length. Its entrance is about 200 yards up a small tributary entering the Santa Rosalia Arroyo on the north side. The entrance had caved in, leaving about a two foot high space through which we had to crawl into the shaft. As we passed down the tunnel we had to traverse another caving at half its length and then a pit about 50 feet from its end. The pit was about 25 feet deep and led to another other lower level which had been blocked by the storm of 1931. When we had gone about 30 yards from the entrance I saw several bats flying away from us into the mine interior. We pursued them to the end of the shaft where we found that their number had multiplied to about 20. We were suc- cessful in netting only three of them which turned out to be Leptonycteris. Upon nearing the entrance, on the way out we saw the large group of bats that had flown past us congregating about the mine entrance, a few flying out. Dr. Benham was