TABLE OF CONTENTS 



INTRODUCTORY AND EXPLANATORY 



Use of scientific names, xvi ; estimates of age of earth, xvii ; 

 restorations by Mr. Knight, xviii ; Works of Reference, xix. 



I. FOSSILS, AND HOW THEY ARE FORMED 



Definition of fossils, 1 ; fossils may be indications of animals or 

 plants, 2 ; casts and impressions, 3 ; why fossUs are not more 

 abundant, 4; conditions under which fossils are formed, 5; 

 enemies of bones, 6 ; Dinosaurs engulfed in quicksand, 8 ; 

 formation of fossils, 9; petrified bodies frauds, 10; natural 

 casts, 10; leaves, 13; incrustations, 14; destruction of fossils, 

 15; references, 17. 



II. THE EARLIEST KNOWN VERTEBRATES 



Methods of interrogating Nature, 18 ; thickness of sedimen- 

 tary rocks, 20 ; earliest traces of life, 21 ; early vertebrates 

 difficult of preservation, 22 ; armored fishes, 23 ; abundance 

 of early fishes, 25 ; destruction of fish, 26 ; carboniferous 

 sharks, 29 ; known mostly from teeth and spines, 30 ; refer- 

 ences, 32. 



III. IMPRESSIONS OF THE PAST 



Records of extinct animals, 33 ; earliest traces of animal life, 

 34 ; formation of tracks, 35 ; tracks in all strata, 36 ; discov- 

 ery of tracks, 37 ; tracks of Dinosaurs, 39 ; species named 

 from tracks, 41 ; footprints aid in determining attitude of ani- 

 mals, 43 ; tracks at Carson City, 45 ; references, 47. 



