146 Geological Society : — 



they are inferior in that respect to the Faroes. The long level lines 

 of basalt-sheets furnish, as it were, datum-lines from which the extent 

 of erosion can be estimated and even measured. There is certainly 

 no other area in Europe where the study of the combined influence 

 of atmospheric and marine denudation can be so admirably pro- 

 secuted, and where the imagination, kindled to enthusiasm by the 

 contemplation of such scenery, can be so constantly and imperiously 

 controlled by the accurate observation of ascertainable fact. 



2. ' The British Silurian Species of Acidasjpu? By Philip Lake, 

 Esq., M.A., F.G.S. 



January 8th, 1896.— Dr. Henry Woodward, F.R.S., President, 

 in the Chair. 



The following communications were read : — 



1. 'A Delimitation of the Cenomanian, being a Comparison of the 

 Corresponding Beds in Southern England and Western France.' By 

 A. J. Jukes-Browne, Esq., B.A., F.G.S., and William Hill, Esq., 

 F.G.S. 



The object of the authors is to compare the beds which form the 

 lower part of the Upper Cretaceous Series in those parts of Southern 

 England and Western France which are nearest to one another. 

 They briefly trace the history of English and French geological 

 research, and remark that even at the present time French geologists 

 are not agreed as to the beds to be included in their i etage Ceno- 

 manien.' 



The authors feel justified in taking the English succession as a 

 standard, and endeavour to show that the French succession is in 

 accord with it, believing that the confusion of French geologists has 

 arisen from their having taken a set of arenaceous shallow-water 

 beds as the standard of their Cenomanian stage, in a district where 

 these form the local base of the Cretaceous System, and where the 

 typical Albien fauna does not exist. 



Commencing with the English sections, they describe such as serve 

 to establish the succession in the Isle of Wight, Dorset, and Devon, 

 pointing out that the Gault and Upper Greensand are everywhere 

 so inseparably united that it is difficult even to assign limits to the 

 component zones ; further, that the Lower Chalk is clearly marked 

 off from this group, and that no classification can be accepted in 

 England which does not recognize the clear and natural line of 

 division at the base of the Chalk. 



In Devonshire the representative of the Lower Chalk is found 

 in a set of arenaceous deposits which contain a remarkable 

 fauna, some of the fossils being such as occur in the Upper Green- 

 sand, some in the Chalk Marl, while many have not been found 

 elsewhere in England, but occur in the Cenomanian of France and 

 in the Tourtia of Tournay. This Devonshire ' Cenomanian ' includes 



