170 



c. A hard, light brown, fine-grained, oolitic, sandy 



Limestone, containing fossils 8 



TJppEK Lias Sands = Jtjkensis Zone. 



D. A coarse dark brown calcareo-siliceous rock, full 



of small dark grains of hydrate of iron. It 

 contains an immense number of Ammonites, 

 Nautili, and Belemnites 4 6 



E. A hard brown mudstone, with rows of irregular 



nodules, of micaceo-ferrugiaous sandstone ... 9 



F. Fine, brown, and yellowish micaceous sands, 



passing into greyish coloured micaceous sands, 

 with inconstant bands of greyish calcareous 

 sandstone, which are sometimes fossiliferous ... 150 0? 



Zone of Ammonites communis. 



0. Blue clay and shale, with Ammonites 80 



Zone op Ammonites makgaeitatus. 



H. Marlstone, a hard calcareous sandstone, resting on 

 brown and grey sands, with bands and nodules 

 of ferruginous sandstone 150 



Zone of Ammonites capricokntjs. 



1. Dark shaly clays of the Middle Lias, forming the 



western slope of the hill 



In our comparison of the different zones of the Lias formation 

 I have endeavoured to demonstrate the strict correlation of the 

 different strata entering into its composition, and have shewn 

 how closely the terrains in the Cote-d'Or agree with their 

 equivalents in Gloucestershire. I now proceed to the examina- 

 tion of the great Jurassic series so well developed in France, 

 Germany, and Switzerland ; in this group of deposits, however, 

 we shall find the study much more difficult, arising from a 

 diversity of opinion among authors on the sub-division of the 

 formations, and their true relation to the standard English 

 type ; the geologists of these different countries having formed 

 opinions on the limits and development of certain subordinate 



