Geology 



of life than those of the Palaeozoic, but yet different from, 

 and more primitive than, those which exist to-day. These, 

 the middle forms of life, give the name to the Mesozoic. 



Many plants and animals similar in type to the 

 present-day or "Recent" fauna and flora came into 

 existence in the Eocene Period, the earliest period of 

 the Cainozoic Era. The word Cainozoic indicates 

 " recent life." 



The rocks of each of these great groups are sub- 

 divided into " formations," each marked by the presence 

 of certain well-defined groups of fossils, and the forma- 

 tions are in their turn'divided into " series," which again 

 possess a characteristic fauna. 



The following table will indicate this mode of 

 classification and at the same time serve for purposes 

 of reference. The newest rocks have been placed at 

 the top and the oldest at the bottom, as that is the 

 position in which they occur in the Earth's crust. 



THE GEOLOGICAL RECORD 



Cainozoic < 



fRecent 

 Pleistocene 

 Pliocene 

 Miocene 

 Oligocene 

 Eocene 



Cretaceous 



Mesozoic * 



Jurassic 



Triassic 



fChalk 



Upper Greensand 

 Gault 



Lower Greensand 

 Wealden 

 Oolites 

 Lias 



{"Rhsetic 

 Keuper 

 Muschelkalk 

 Bunter 



68 



