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. 



Fig. 159- 



- Purbeck Beds. 

 Portland Beds. 



--Kimmeridge Clay. 





Oxford Clay. 



Cornbrash and Forest-marble. 



-Great Oolite. 



Fuller's Earth. 



Inferior Oolite. 



- Upper Lias. 



j Middle Lias (Marlstone 



( series). 



Lower Lias. 



( Rbaetic Marls (" White 

 \ Lias"). 



The plants of the Jurassic period consist principally of 

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



