170 NEW YORK STATE MUSEUM 



known as Carboniferous in Pennsylvania, should be referred to 

 this horizon. 



Life of the Carboniferous 



Animals 



Foraminifera were abundant. Sponges were well represented. 

 Reef building corals were scarce. Oinoids were abundant. 



Brachiopods were large and numerous. 



Mollusks were prominently represented by cephalopods. 



The fishes of the Carboniferous were very numerous and were 

 principally sharks and ganoids. 



The presence of amphibians was the prominent feature in the 

 life of the Carboniferous; their bones occur in the coal measures. 

 The largest were about the size of alligators. 



Before the close of the Carboniferous, reptiles appeared. 



Plants 



Vegetable life was well represented by ferns, lycopods, equi- 

 setae, conifers and cycads. These were the plants which sup- 

 plied the vegetable tissue which forms the coal beds. 



Mesozoic Time 



The Mesozoic presents a marked contrast to the Palaeozoic. 

 The sea was peopled with fishes. Cephalopods were most promi- 

 nent among the mollusks. True reptiles which appeared in 

 the Permian were large and numerous and reached their highest 

 development.. Mammals appeared as a new element but held a 

 subordinate position. They were at first quite small. 



There was a complete change in the vegetation. Sigillaria and 

 calamites disappeared and the age of gymnosperms succeeded 

 that of acrogens or pteridophyta. 



Arborescent conifers were very large and abundant. The 

 cycads occupied the place of the palms of the present day. 



The Mesozoic series includes the Triassic, Jurassic and Cretace- 

 ous systems. 



