MEMOIRS 



OF THE 



American Museum of Natural History. 



New Series, Volume II. 



PART I. — EQUIDiE OF THE OLIGOCENE, MIOCENE, AND PLIOCENE OF NORTH 



AMERICA, ICONOGRAPHIC TYPE REVISION. 



By Henry Fairfield Osborn. 



Honorary Curator of Vertebrate Palaeontology in the American Museum of Natural History, Vertebrate 



Paleontologist U. S. Geological Survey. 



Plates 1-54, and 173 Text Figures. 



CONTENTS. 



Page. 



Preface 2 



Introduction, tooth morphology of the fossil Equidse 3-7 



Chief geologic horizons, formations, levels, and life zones containing remains of the Equidse .... 8-34 



Systematic revision and type figures of the species 35-213 



Mesohippus .................. 36-50 



Miohippus 51-68 



Kalobatippus .................. 69-73 



Parahippus .................. 74-97 



Merychippus 98-126 



Protohippus 127-145 



Pliohippus 146-172 



Hipparion 173-202 



Hypohippus .................. 203-210 



Archwohippus .................. 211-213 



Index 214-217 



i 



