3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 478–530, 49 figures in text, 18 tables. October 10, 1951.
4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531–649, 7 figures in text, 2 tables. October 10, 1951.
Index. Pp. 651–681.
*Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp. 1–466, 41 plates, 31 figures in text. December 27, 1951.
Vol. 5. Nos. 1–37 and index. Pp. 1–676, 1951–1953.
*Vol. 6. (Complete) Mammals of Utah, taxonomy and distribution. By Stephen D. Durrant. Pp. 1–549, 91 figures in text, 30 tables. August 10, 1952.
Vol. 7. *1. Mammals of Kansas. By E. Lendell Cockrum. Pp. 1–303, 73 figures in text, 37 tables. August 25, 1952.
2. Ecology of the opossum on a natural area in northeastern Kansas. By Henry S. Fitch and Lewis L. Sandidge. Pp. 305–338, 5 figures in text. August 24, 1953.
3. The silky pocket mice (Perognathus flavus) of Mexico. By Rollin H. Baker. Pp. 339–347, 1 figure in text. February 15, 1954.
4. North American jumping mice (Genus Zapus). By Philip H. Krutzsch. Pp. 349–472, 47 figures in text, 4 tables, April 21, 1954.