Subspeciation in the Kangaroo Rat, Dipodomys ordii BY HENRY W. SETZER University of Kansas Publications Museum of Natural History Volume 1, No. 23, pp. 473-573, 27 figures in text, 7 tables December 27, 1949 University of Kansas LAWRENCE 1949 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Edward H. Taylor, Robert W. Wilson Volume 1, No. 23, pp. 473-573, 27 figures in text, 7 tables December 27, 1949 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1949 22-6114 Subspeciation in the Kangaroo Rat, Dipodomys ordii By HENRY W. SETZER CONTENTS PAGE Introduction 477 Methods and Acknowledgments 478 Paleontology 480 Phylogeny of the Species of the Genus 484 Dispersal of the Several Species 498 Subspeciation 499