1869.] COQUAND CEETACEOUS STRATA. 237 



Eurypterus- zone at Stoke Edith, At Ledbury, according to Mr. 

 Lightbody, there is a thickness of 300 feet between the Downton 

 Sandstone and the passage-beds. At Stoke I could find no trace of 

 the bone-bed, though it appears at Hagley, not far off, and at other 

 places surrounding the Woolhope elevation. 



March 24, 1869. 



The Rev. Samuel Norwood, B.A., Head Master of the Royal 

 Grammar School, Whalley, Lancashire, was elected a Fellow of the 

 Society. 



The following communications were read : — 



1. The Cretaceous Strata of England and the IS'orth of Erance 

 compared with those of the West, South- West, and South of 

 France, and the JSTorth of Africa. By Prof. Henri Coquand, 

 Marseilles. 



[Translated and communicated by J. W. Flower, Esq., F.G.S.] 



English geologists may fairly claim the honour of having esta- 

 blished in the Cretaceous formation the great divisions which are now 

 generally received, and which find on the European continent their 

 direct application to the strata of the same period. This is more 

 especially true as regards the basin of the Seine, which is in fact 

 but an appendage of that of England. 



When, however, we leave the valley of the Seine and approach 

 the Departments of the west of France, we find that the divisions 

 previously recognized become altogether insufficient. For example, 

 between the first beds with Inoceramus lahiatus (the base of the 

 Lower Chalk) and the highest layers of the chalk marl (with Am-^ 

 monites Mantelli), some important beds of sandstone and limestone, 

 characterized by Ostrea hiauriculata, Lamk., intervene. These beds 

 are known by the name of the Grbs du Mans, and they seem to be 

 wanting in England, as also in the north of France. 



If from the Anglo -Parisian basin we pass to that of the Pyrenees, 

 of which the Departments of the two Charentes and the Dordogne 

 constitute the northern limits, at least in a geological point of view, 

 we meet with still more important modifications. Thus, the Gres 

 du Mans are here more highly developed, and force themselves upon 

 the notice of the palaeontologist on account of the great abundance 

 of Rudistes which they contain, such as SphceruUtes foliaceus, 

 Lamk., Caprina adversa, C. M. D'Orb., Caprina Fleuriausii, Mono- 

 pleura polyconilites, <fcc. Above this layer, of which the Oyster-beds 

 {Ostrea biauriculata, Lamk., and Ostrea jiahella, D'Orb.) invariably 

 form one of the constituents, are the marly beds of the Lower Chalk 

 with Inoceramus lahiatus, a stratum which in England and in 

 Picardy comprises in its upper portion the layers with Ostrea acuti- 



s2 



