Vol. 11. 1. The systematic status of the colubrid snake, Leptodeira discolor Guenther. By William E. Duellman. Pp. 1-9, 4 figs. July 14, 1958. 2. Natural history of the six-lined racerunner, Cnemidophorus sexlineatus. By Henry S. Fitch. Pp. 11-62, 9 figs., 9 tables. September 19, 1958. 3. Home ranges, territories, and seasonal movements of vertebrates of the Natural History Reservation. By Henry S. Fitch. Pp. 63-326, 6 plates, 24 figures in text, 3 tables. December 12, 1958. 4. A new snake of the genus Geophis from Chihuahua, Mexico. By John M. Legler. Pp. 327-334, 2 figures in text. January 28, 1959. 5. A new tortoise, genus Gopherus, from north-central Mexico. By John M. Legler. Pp. 335-343, 2 plates. April 24, 1959. 6. Fishes of Chautauqua, Cowley and Elk counties, Kansas. By Artie L. Metcalf. Pp. 345-400, 2 plates, 2 figures in text, 10 tables. May 6, 1959. More numbers will appear in Volume 11. * * * * * TRANSCRIBER'S NOTES 1. Passages in italics are surrounded by _underscores_. 2. Passages in bold-italics are surrounded by #bold#. 3. Images and tables have been moved from the middle of a paragraph to the closest paragraph break.