THE JURASSIC PERIOD. 



229 



characterised by special life-forms than has as yet been found 

 practicable in the case of any other rock-series. 



GENERALISED SECTION OF THE JURASSIC ROCKS 

 OF ENGLAND. 



-Purbeck Beds. 



Portland Beds. 



Kimmeridge Clay. 



Coral- Rag. 



Oxford Clay. 



-Cornbrash and Forest-marble. 

 -Great Oolite. 



--Fuller's Earth. 

 -Inferior Oolite. 



Upper Lias. 



Middle Lias (Marlstone 



series). 



Lower Lius. 



Rhsetic Marls (" White 

 Lias "). 



The plants of the Jurassic period consist principally of 

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



