In preparing my accounts of both living and extinct forms I have nearly invariably consulted the original authorities, and have often supplemented or verified these accounts by my own dissections at the Zoological Society's Gardens. My rule has not, however, been invariable in this matter, inasmuch as there exist two recent and trustworthy text-books of Mammalian Palaeontology--Professor Zittel's _Handbuch der Palaeontologie_, and Dr. A. Smith Woodward's manual, _Outlines of Vertebrate Palaeontology_, in the Cambridge Biological Series. Where the name of a genus only or its range, or merely one or two facts about it, are mentioned, I have not thought it necessary to go further than these two works. But a good deal has been done even since the appearance of these two volumes which it will be found that I have not ignored. I have to thank my editors for the trouble which they have taken in the revision of the proofs and for many suggestions. To Professor Osborn, of Columbia University, New York, I am indebted for some kind suggestions. My daughter Iris has assisted me in various ways. Finally, I desire to express my indebtedness to Mr. Dixon and to Mr. M. P. Parker for the care which they have taken in the preparation of the figures which were drawn by them especially for this work. FRANK E. BEDDARD. LONDON, _February 28, 1902_. * * * * * {v} CONTENTS Page PREFACE iii SCHEME OF THE CLASSIFICATION ADOPTED IN THIS BOOK ix CHAPTER I INTRODUCTORY 1 CHAPTER II STRUCTURE AND PRESENT DISTRIBUTION OF THE MAMMALIA 5 CHAPTER III THE POSSIBLE FORERUNNERS OF THE MAMMALIA 90 CHAPTER IV THE DAWN OF MAMMALIAN LIFE 96 CHAPTER V THE EXISTING ORDERS OF MAMMALS: PROTOTHERIA--MONOTREMATA 105 CHAPTER VI INTRODUCTION TO THE SUB-CLASS EUTHERIA 116 CHAPTER VII EUTHERIA--MARSUPIALIA 122 {vi} CHAPTER VIII EDENTATA--GANODONTA 161 CHAPTER IX UNGULATA--CONDYLARTHRA--AMBLYPODA--ANCYLOPODA--TYPOTHERIA-- TOXODONTIA--PROBOSCIDEA--HYRACOIDEA 195 CHAPTER X UNGULATA (_continued_)--PERISSODACTYLA (ODD-TOED UNGULATES)-- LITOPTERNA 235 CHAPTER XI UNGULATA (_continued_)--ARTIODACTYLA (EVEN-TOED UNGULATES)--SIRENIA 269 CHAPTER XII CETACEA--WHALES AND DOLPHINS 339 CHAPTER XIII CARNIVORA--FISSIPEDIA 386 CHAPTER XIV