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 
II. 
Definition of fossils, 1; fossils may be indications of animals or 
plants, 2; casts and impressions, 3; why fossils 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. 
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. 
Vv 
