Part 12

2. A distributional study of the amphibians of the isthmus of Tehuantepec, Mexico. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figs. August 16, 1960.

3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahuila, Mexico. By John M. Legler. Pp. 73-84, pls. 9-12, 3 figures in text. August 16, 1960.

4. Autecology of the Copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960.

5. Occurrence of the Garter Snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in text. February 10, 1961.

6. Fishes of the Wakarusa River in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-32 2, 1 figure in text. February 10, 1961.

7. Geographic variation in the North American Cyprinid Fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures in text. February 10, 1961.

8. Descriptions of two species of frogs, Genus Ptychohyla--studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pls. 25, 2 figures in text. April 27, 1961.

More numbers will appear in volume 13.

Vol. 14. 1. Neotropical bats from western Mexico. By Sydney Anderson. Pp. 1-8. October 24, 1960.

2. Geographic variation in the harvest mouse Reithrodontomys megalotis on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr. and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961.

3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1-2, 3 figures in text. July 24, 1961.

More numbers will appear in volume 14.