Teranscriber's Notes To denote superscripts a carat (^) is used. _Text_ - Italics =Text= - Bold UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 7, No. 4, pp. 349-472, 47 figures in text, 4 tables April 21, 1954 North American Jumping Mice (Genus Zapus) BY PHILIP H. KRUTZSCH UNIVERSITY OF KANSAS LAWRENCE 1954 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Robert W. Wilson Volume 7, No. 4, pp. 349-472, 47 figures in text, 4 tables Published April 21, 1954 UNIVERSITY OF KANSAS LAWRENCE, KANSAS PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1954 25-1128 North American Jumping Mice (Genus Zapus) by Philip H. Krutzsch CONTENTS PAGE Introduction 351 Materials, Methods, and Acknowledgments 352 Paleontology of the Genus 355 Relationships, Distribution, and Speciation 356 Annotated List of Specific and Subspecific Names 369 Characters of Taxonomic Worth 371 Nongeographic Variation 376 Check-List of the Species and Subspecies of the Genus Zapus 382 Genus Zapus 382 Artificial Key to the Species of the Genus Zapus 384 Systematic Accounts of Species and Subspecies 385 _Zapus trinotatus_ 385 _Zapus princeps_ 394 _Zapus hudsonius_ 420 Tables of Measurements 455 Literature Cited 466 INTRODUCTION The jumping mice (Genus _Zapus_) are widely distributed over northern North America, occurring as far north as the Arctic Circle and as far south as Georgia, Missouri, Oklahoma, New Mexico, Arizona, and central California. In some years these small rodents are locally common in moist places that are either grassy or weedy; the jumping mice are notable for the much enlarged hind legs and the exceptionally long tail. Members of the Genus as a whole have received no serious comprehensive taxonomic attention in the 54 years since Preble's (1899) revisionary work. In this time 15 new names have been proposed, mostly for subspecies, and only a few attempts have been made at grouping related named kinds.