1898] ALBIAN AND CENOMANIAN IN FRANCE 197 



one fauna at Le Mans, but then he also thought the Albian was not 

 present at Havre, where it is now admitted to exist. In the same way 

 it may be necessary to admit the existence of Albian at Le Mans. 



Now what does present itself at Le Mans ? I will quote the 

 words of Mr Dollfus : " At Le Mans the base of the Cenomanian 

 c< msists of sands containing Ostrca vesiculosa, Nautilus subelegans, 

 Pecten asper, Ammonites inflatus, etc. These sands rest on Oxfordian 

 beds with Bhynchondla varians, without the interposition of any beds 

 belonging to the Lower Cretaceous ; this lower limit is therefore 

 very clearly marked, for it is based on a considerable stratigraphical 

 break." But what kind of break is here ? There is no break in 

 the Cretaceous series, only an incomplete condition, from the absence 

 of everything below a certain horizon in the series. 



It is this very break or hiatus which is a source of difficulty, 

 for, if the succession in the Sarthe had been complete, I do not think 

 this discussion about the base of the Cenomanian would ever have 

 arisen. French geologists have hitherto taken for granted that 

 everything at Le Mans must be Cenomanian down to the local 

 base. It is this to which I object : this assertion must be proved, 

 not taken for granted. My position is this, that the delimitation 

 of the Cenomanian cannot logically or properly be settled in La 

 Sarthe. Its upper limit can be determined there because both 

 Cenomanian and Turonian are fully developed ; but its lower limit 

 cannot be determined there ; this must be done in some other 

 region where both Albian and Cenomanian are fully represented. 



I do not ask my French confreres to come to England for the 

 decision of this cpuestion, nor do I ask them to accept a new name : 

 I recognise that it is primarily a French business, and I will accept 

 the evidence of the French strata. But I do say this, that the 

 matter must be judged by the evidence of the fossils found in the 

 region which is selected for trial, and that the fossils of La Sarthe 

 must be left out of the account while the comparison is being made 

 between the fauna of the zone of A. inflatus with the faunas of the 

 beds above and below it. 



Where then in France should this comparison be made ? Not 

 at Havre where the Albian is little developed ; not in the Pays de 

 Bray where fossils are rare in the Gaize. It is to the east of 

 France that Mr Dollfus himself appeals on this point, maintaining that 

 the fauna of the zone of A. inflatus at Wissant and in the Gaize de 

 l'Argonne is so different from that of the zone of A. intrrruptvs, that 

 it must be grouped with Cenomanian, not with the Albian. I accept 

 this test, but I do not come to the same conclusion. 



Let us take first the Gaize de l'Argonne. Mr Dollfus says that 

 the list published by Mr Barrois shows that 51 species are Albian 

 (Gault Tnf('rieur) and that 70 are Cenomanian; but the latter figure is 



