Vol. 52.] A DELIMITATION OP THE CENOMANIAN. 103 



and suggested that more accurate views might be obtained by an 

 investigation of some of the principal exposures along a traverse 

 from the coast in the direction of Lisieux, Vimoutiers, aud Mortagne. 

 In planning out the route of this traverse we owe thanks to 

 M. G. F. Dollfus, of Paris, and M. Bizet, of Belleme, for advice 

 and information regarding the best localities to visit. The cliffs 

 between Cape La Heve and Etretat were first studied in detail, and 

 subsequently two excursions were made to localities in the Calvados 

 and Orne, between Honfleur and Mortagne. 



[Note. — It should be mentioned that the examination of the 

 French sections was accomplished entirely by Mr. Hill, and that the 

 exposures in the Calvados had to be discovered without guidance, 

 except so far as the outcrops were shown on the sheets of the Carte 

 geologique detaillee de la France. The Devon coast-sections were 

 worked out by myself in 1894 for the Geological Survey, and the 

 Director- General kindly permits us to publish some of the infor- 

 mation then obtained. — A. J. J.-JB.] 



In arranging our descriptive notes for comparison we have thought 

 it best to place the English sections first, because this part of the 

 Cretaceous series is much more complete, more frequently exposed 

 in coast-sections, and more clearly divisible into two distinct portions 

 or stages than it is in France. Consequently we feel justified in 

 taking the English succession as a standard, and in endeavouring to 

 bring the French succession into accord with ours. We believe 

 that we have succeeded in doing this, and that as a result we shall 

 have supplied French geologists with a better and more definite base- 

 line for their Cenomanian stage. We think that the present state 

 of confusion has arisen from their having adopted an opposite course, 

 for they have taken a local and incomplete set of beds as a standard, 

 and have tried to fit the more normal and complete succession 

 with this unsuitable type. It is just as if we had taken the Devon 

 type of these two stages as a standard, and had endeavoured to 

 correlate the Gault and Lower Chalk of Folkestone with that local 

 and peculiar type — without studying the intervening exposures. 



II. A brief Description of some Sections on the South 

 Coast of England. 



The sections which most clearly exhibit the relationship of the 

 Gault, Upper Greensand, and Lower Chalk are those on the coasts 

 of the Isle of Wight, Dorset, and Devon. 



1. Isle of Wight. 



The stratigraphic succession of these groups in the Isle of Wight 

 is fairly well known on both sides of the Channel, to the French 

 from the writings of Dr. Barrois, and to us from those and from 

 the second edition of the Geological Survey memoir on the island ; 

 so that we need only call attention to such points as have a 

 special bearing on our present purpose. 



