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.