Pocket Gophers as Enemies of Trees. (Separate 506, Yearbook 1909.) Price 5 cents. The Jack Rabbits of the United States. (Biological Survey Bulletin 8.) Price 10 cents. Economic Study of Field Mice, genus _Microtus_. (Biological Survey Bulletin 31.) Price 15 cents. The Brown Rat in the United States. (Biological Survey Bulletin 33.) Price 15 cents. Directions for the Destruction of Wolves and Coyotes. (Biological Survey Circular 55.) Price 5 cents. The California Ground Squirrel. (Biological Survey Circular 76.) Price 5 cents. Seed-eating Mammals in Relation to Reforestation. (Biological Survey Circular 78.) Price 5 cents. Mammals of Bitterroot Valley, Montana, in Their Relation to Spotted Fever. (Biological Survey Circular 82.) Price 5 cents.