University of Kansas Publications, Museum of Natural History
Editors: E. Raymond Hall, Chairman, Henry S. Fitch,
Robert W. Wilson
Volume 9, No. 23, pp. 579-670, 4 pls., 12 figs. in text
Published June 16, 1960
University of Kansas
Lawrence, Kansas
PRINTED IN
THE STATE PRINTING PLANT
TOPEKA, KANSAS
1960

28-3030

Speciation and Evolution of the Pygmy Mice, Genus Baiomys

BY

ROBERT L. PACKARD

CONTENTS

PAGE
[Introduction]583
[Materials, Methods and Acknowledgments]584
[Paleontology of the Genus]587
[Baiomys sawrockensis]588
[Baiomys rexroadi]589
[Baiomys kolbi]590
[Baiomys brachygnathus]590
[Baiomys minimus]591
[Phyletic trends]592
[Non-Geographic Variation]595
[Variation with age]595
[Secondary sexual variation]597
[Individual variation]597
[Pelage and molts]598
[Taxonomic Characters and Relationships]600
[External parts]600
[Pelage]600
[Skull]600
[Teeth]601
[Hyoid apparatus]601
[Baculum]603
[Auditory ossicles]605
[Genus Baiomys]607
[Systematic Accounts of Species and Subspecies]608
[Baiomys musculus]608
[Baiomys musculus brunneus]612
[Baiomys musculus grisescens]614
[Baiomys musculus handleyi]617
[Baiomys musculus infernatis]618
[Baiomys musculus musculus]620
[Baiomys musculus nigrescens]623
[Baiomys musculus pallidus] 625
[Baiomys musculus pullus]628
[Baiomys taylori]630
[Baiomys taylori allex]633
[Baiomys taylori analogous]637
[Baiomys taylori ater]640
[Baiomys taylori canutus]643
[Baiomys taylori fuliginatus]645
[Baiomys taylori paulus]647
[Baiomys taylori subater]650
[Baiomys taylori taylori]651
[Evolution and Speciation]655
[Formation of the Recent Species]658
[Areas of present differentiation]661
[Zoogeographic position]661
[Conclusions]664
[Literature Cited]665