Transcriber's note: Text enclosed by underscores is in italics (_italics_). Text enclosed by equal signs is in bold face (=bold=). Throughout, an asterisk (*) before a name denotes extinct genera/species. * * * * * UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Vol. 16, No. 6, pp. 473-579, 9 figures in text August 5, 1968 Evolution and Classification of the Pocket Gophers of the Subfamily Geomyinae BY ROBERT J. RUSSELL UNIVERSITY OF KANSAS LAWRENCE 1968 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Frank B. Cross, J. Knox Jones, Jr. Volume 16, No. 6, pp. 473-579, 9 figs. Published August 5, 1968 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY ROBERT R. (BOB) SANDERS, STATE PRINTER TOPEKA, KANSAS 1968 [Illustration: Look for the Union label] 31-4628 Evolution and Classification of the Pocket Gophers of the Subfamily Geomyinae BY ROBERT J. RUSSELL CONTENTS PAGE INTRODUCTION 477 MATERIALS AND ACKNOWLEDGMENTS 477 TAXONOMIC CHARACTERS 478 Prismatic character of molars 478 Character of enamel patterns 479 Grooving of incisors 480 Masseteric ridge and fossa 480 Basitemporal fossa 481 Specializations of skull 481 FOSSIL RECORD 484 Miocene 485 Pliocene 486 Pleistocene 490 Thomomys 492 Zygogeomys 496 Geomys 496 Pappogeomys 503 Orthogeomys 504 HISTORY OF CLASSIFICATIONS 505