HISTORICAL PALEONTOLOGY. 



GENERALIZED SECTION OF THE JURASSIC ROCKS 

 OF ENGLAND. 



Fig. 159. 



Purbeck Beds. 



^ Portland Beds. 



Kimmeridge Clay. 



Coral-Rag. 



Oxford Clay. 



| Cornbrash and Forest- 

 1 marble. 

 Great Oolite. 



Fuller's Earth. 

 Inferior Oolite. 



Upper Lias. 



Middle Lias (Marl- 

 stone series). 



... Lower Lias. 



(Rhaetic Marls ("White 

 " 1 Lias"). 



The plants of the Jurassic period consist principally of 

 Ferns, Cycads, and Conifers agreeing in this respect, there- 

 fore, with those of the preceding Triassic formation. The 

 Ferns are very abundant, and belong partly to old and partly 

 to new genera. The Cycads are also very abundant, and, on 





