Upper Jurassic Rocks of England and the Continent. 73 



gemma and massive corals, which is gradually introduced in going 

 west. This part of the series in the Haute Marne has been de- 

 scribed as very different ; but the author did not at all agree with 

 M. Tombeck's stratigraphical determination, and considers the " Oolite 

 de la Nothe " no more than the continuation of the Supracoralline 

 Diceras-be&s, which he considers to uniformly overlie and never 

 to underlie the Am. marantianus marls, which latter are Oxfordian. 

 In fact nothing abnormal occurs in this Department. The whole 

 series has a tendency to degenerate into barren lithographic lime- 

 stones, in which distinctions are lost. The Astartian and Virgulian 

 beds were traced through this range, the latter seldom showing any 

 well-marked Pterocerian division, and the former being most con- 

 nected with the overlying series. Above these are limestones 

 hitherto called " Portlandian," in which two zones are constant; 

 but above all are vacuolar Oolites, which alone may be truly cor- 

 related with the Portland rocks of England. The whole of the beds 

 in this range are eminently calcareous, a true clay being scarcely 

 anywhere seen. 



2. The Oharentes. — In these two Departments the lower portion 

 is very calcareous, and the distinction of one part from another very 

 slight ; but the highest portion, both near Cognac and on the He 

 d'Oleron, yields beds which may be paralleled with our true English 

 Portland rocks. 



3. Normandy. — The complete sequence has here been made out, 

 from the true Oxford Clay of Dives to the Virgulian of Havre ; and 

 the similarity of the whole to the sequence in Dorsetshire is very 

 remarkable. " The Trouville Oolite " is the exact representative of 

 the " Osmington Oolites " with the Nothe Grits below ; but the 

 place of the Sandsfoot clay is taken by the true Coral Rag, whose 

 right position in the Weymouth section is hereby determined. The 

 Supracoralline beds are the sands of Glos ; and the Astartian beds are 

 the Trigonia-heds of Havre, which are the exact representatives 

 of the " Kimmeridge passage-beds." 



4. The Pays de Bray. — Nothing below the Yirgulian is here seen ; 

 and the commencement of the so-called " Portland beds" was con- 

 sidered by the author to be at a lower level than it is placed by M. 

 Lapparent, on account of the similarity to beds at Boulogne. The true 

 Portland rocks occur as ferruginous sandstones with Trigonia gibbosa. 



5. Boulonnais. — The Houllefort limestone was correlated with the 

 Osmington Oolite. The Coral Bag of Brucdale was considered equi- 

 valent to that of the Mont des Boucards, the so-called limestones of 

 the latter place being Supracoralline. The Nerinaean Oolite and the 

 Gres de Wirvigne represent the Astartian. The higher parts of the 

 series have been already correlated. 



Erom this study it was proposed : — that the " Lower Calcareous 

 Grit " and almost all the Coralline Oolite should be placed in the 

 Oxfordian series as the upper division, under the name " Oxford 

 Grit " and " Oxford Oolite ;" that the Corallian consists of two parts, 

 the Coral Hag and the Supracoralline beds ; that the Kimmeridgian 

 should include the Astartian and Yirgulian, the Pterocerian being 



