﻿JURASSIC AND TRIASSIC BRACHIOPODA. 



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SUPPLEMENT TO THE BRITISH JURASSIC AND TRIASSIC 



BRACHIOPODA. 



The first portion of my Monograph of the British Oolitic and Liassic Brachiopoda 

 was published in June, 1851 ; the second part in August, 1852, and the Appendix in 

 May, 1855. Much additional information has been acquired during the intervening years ; 

 and so many fresh species and better specimens have been discovered that it will be 

 necessary to follow the plan adopted in the Cretaceous Supplement, and thoroughly 

 review the subject. 



Lyell divides the Jurassic and Triassic formations of Great Britain in the following 

 manner : 



Upper Oolite. 



Cornbrash and Porest-marble. 



^ Inferior Oolite. 



Lias. 



Trias. 



* Between the Coral-rag and Oxford Clay the Lower Calcareous Grit is well developed in Yorkshire. 



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