CONTENTS. PART I.—GENERAL INTRODUCTION. CHAPTER I. PAGE Definition of Palaeontology—Definition of the term “ fossil ”—Pro cesses of Fossilisation—Definition of “rock”—Classification of Rocks, .......... 1-5 CHAPTER II. Characters of the Sedimentary Rocks—Mode of formation of the Sedi mentary Rocks—Definition of the term “ formation ”—Chief divisions of the Aqueous Rocks—Mechanically-formed Rocks— Chemically-formed Rocks—Organically-formed Rocks—Different ages of the Aqueous Rocks—Chronological Succession of the Stratified Rocks, ........ v’4 CHAPTER III. Use of the term “contemporaneous,” as applied to groups of beds— General sequence of phenomena at the close of each Geological Period—Migrations—Differences between the fossils of known contemporaneous strata—Geological continuity—Relations be tween the Chalk and the Atlantic Ooze—Reappearance of similar forms of life under similar conditions—Doctrine of “ Colonies,” 14-27 CHAPTER IV. Causes of the Imperfection of the Palaeontological Record—Causes of the absence of certain animals as fossils —Unrepresented time— Unconformity, sequence of phenomena indicated by—Leading examples of unconformity—Thinning out of beds—Sudden ex tinction of Animals—Disappearance of fossils, . . . 27-39 CHAPTER V. Conclusions to be drawn from Fossils—Age of Rocks—Mode of origin of any Fossiliferous bed—Fluviatile, lacustrine, and marine deposits —Conclusions as to Climate, 40-44