OF THE SWISS JURA AND ENGLAND. 



253 



Prof. Blake, referring to Waagen's classification of the British 

 Jurassics, states that he can only make out a two-fold division of the 

 Kimeridge Clay — an upper, which agrees with that of Waagen, and a 

 lower, which includes the Middle and part of the Lower Kimeridge 

 of TVaagen ; whilst the remainder of the Lower Kimeridge, together 

 with a portion of the underlying zone of Cid. florigemma, Blake in- 

 cludes in his Kimeridge Passage-beds (Q,. J. G. S. vol. xxxi. p. 197). 



The following table is taken from Renevier's " Tableaux des Ter- 

 rains sedimentaires " (tab. no. 5, Bull. Soc. Yaud. vol. xiii.) : — 



England. 



Purbeck Beds. 



Dirt Bed of Portland. 



Jura occidental. 



Marnes a Planorbis Loryi, 

 Marnes a Gypse. 

 Calc. dolomitique a Cor- 

 bula inflexa. 



Portland Stone. 

 Portland Sand. 

 Upper Kimeridge. 



Calcaire Portlandien. 



Kimeridge Clay a Exogyra 

 virgula. 



Marnes a Ostrea virgula 



(Virgulien inferieur). 

 Pterocerien. 





Astartien compacte, &c. 

 Astartien rnarneux. 



Upper Uaic urit et Loral 

 Rag (pars). 



? 



Coralline oolite a Lima 



Tig lull , ot 



Bancs a Cidaris flori- 

 gemma. 



Oolithe coralliene a Ne- 

 rinees et Diceras arie- 

 Una, et 



Calcaires chailleux. 



Terrain a chailles a Glyp- 



ticus hieroglyphicus. 



Calc Grit a Ostrea di- 

 latata. 



n r j- f Pholadomien. 

 Oxfordien 1 Calc> hydpaulique . 

 Oalcaire. y Spong it ie n. 



Oxford-clay a Amm. Dun- 

 cani. 



Marne Oxfordienne a fos- 

 siles pyriteux. 



Kelloway-rock a Aram, cal- 

 loviensis. 



Kellovien ferrugineux a 

 Amm. anceps et Amm. 

 macrocephalus. 



In the subjoined table an attempt has been made to show the 

 correlations of the authors referred to above, and it will be seen that 

 they differ in several important points. 



