RIDGWAY, R. 1912. Color standards and color nomenclature, pp. iii + 43, 53 pls., published by the author. Washington, D. C., 1912. SCHULTZ, J. R. 1938. A late Quaternary mammal fauna from the tar seeps of McKittrick, California. Carnegie Inst., Washington, 487:113-215, 17 pls., 12 figs., July 6, 1938. WARREN, E. R. 1942. The mammals of Colorado, their habits and distribution, pp. xviii + 330, 50 pls., University of Oklahoma Press, Norman, Oklahoma, 1942. WILSON, R. W. 1939. Rodents and Lagomorphs of the late Tertiary Avawatz Fauna, California. Carnegie Inst., Washington, 514:33-38, 1 pl., May 18, 1939. WOOD, A. E. 1935. Evolution and relationship of the heteromyid rodents with new forms from the Tertiary of western North America. Annals Carnegie Museum, 24:73-262, 157 figs., 3 tables, May 13, 1935. _Transmitted May 15, 1948._ 22-6114 Transcriber's note: Gesperrt text is indicated by ~swung dashes~. End of the Project Gutenberg EBook of Speciation in the Kangaroo Rat, Dipodomys ordii, by Henry W. Setzer