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.