TABLE OF STRATIFIED ROCKS 



SHOWING APPROXIMATE THICKNESS. 



MOTH, MASTODON 

 REE TOED HORSE 

 5 lETBABELODON 



< ARSINOITHERIUM OlNOC€RAS 

 X ANCESTORS OF ELEPHANTS 



HORSES t. MAMMALS GENERA 

 LAST ICHTHYOSAURS 



^m GREAT DINOSAURS 



LAST TRIL08ITES 



SCORPIONS 



FIRST FISHES 

 MARINE SCORPION 



'i',///i//t/W,:/,/'/i 



Fig. 41. — A tabular 

 view of the strata 

 of the earth's 

 crust, showing the 

 relative thickness 

 of each " system " 

 or group of stra ta, 

 and the position 

 in which impor- 

 tant animal re- 



FIRST TRILOBITE-S 



mains have been 

 discovered. The 

 rocks are never 

 found lying hori- 

 zontally like this, 

 which is a diagram. 

 In nature they are 

 tilted and crum- 

 pled, but we can 

 make out their 

 thickness and the 

 order in which they 

 lie one over the 

 other. 



