4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129–161, 8 figures in text, 4 tables. December 19, 1957.
5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163–211, pls. 9–10, 1 figure in text. March 12, 1958.
6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213–552, 34 plates, 8 figures in text, 35 tables. November 7, 1958.
7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 558–572, 4 plates, 3 figures in text. May 4, 1959.
8. Natural history of the salamander, Aneides hardyi. By Richard F. Johnston and Schad Gerhard. Pp. 573–585. October 8, 1959.
9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, Mexico. By William E. Duellman. Pp. 587–598, 2 figures in text. May 2, 1960.
10. A taxonomic study of the Middle American Snake, Pituophis deppei. By William E. Duellman. Pp. 599–612, 1 plate, 1 figure in text. May 2, 1960.
Index Pp. 611–626.
Vol. 11. 1. The systematic status of the colubrid snake, Leptodeira discolor Günther. 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.