1898] ALBIAN AND CENOMANIAN IN FRANCE 201 
I only know of two cases where A. varians and A. rostratus are 
said to be associated: one is in the highest bed of the Greensand in 
North Dorset where both are rare. The other is the record by Mr 
Price of A. varians from his bed XI. at Folkestone, but the varians 
was a doubtful specimen and no other has since been found. Mr 
Munier-Chalmas states that A. varians occurs with A. rostratus in 
the East of France, and doubtless it does occur occasionally at the 
summit of the A. vostratus zone. Such occurrences are not rare 
near the junction of two stages, and they only prove that there is 
no hard and fast line separating one fauna from another. It is 
generally conceded that in the delimitation of zones or stages, we 
must be guided by the abundance of certain characteristic species 
not by the mere occurrence of one or two of them. Consequently 
those who argue that the zone of A. rostratus must be Cénomanien 
because A. varians sometimes occurs near the top of it are re- 
versing the rule, and seek to establish a precedent which would 
destroy our principles of classification. 
Mr Dollfus has said “it is an illusion to think that we can ever 
possess a perfect classification which would satisfy geologists of all 
countries.” That is quite true, but it is not an illusion to believe 
that we can frame a classification which will suffice for one strati- 
graphical province or basin of deposition, such as that of England 
or Northern France. 
I do not seek to upset the French nomenclature, on the con- 
trary I recognise that the French will accept no other nomenclature. 
Endeavours have been made to employ it in England, but at present 
that isimpossible. D’Orbigny’s names have been so wrested from their 
original application by the modern French geologists that many English 
geologists think that these names no longer possess any fixity of mean- 
ing ; consequently they oppose the adoption of them. There are of 
course some who see that the alterations are merely personal views 
of grouping, and that the faunistic differences on which the names 
were founded remain the same. So far as the divisions of the Chalk 
are concerned, we may eventually be able to employ the French names, 
and the time will be hastened if our French confréres will restrict the 
Cenomanian to its proper limits; but with respect to the English Gault 
and Greensand I see no alternative but to propose a new name. 
I hope at any rate to have made it clear that I do not advocate 
“a return to antiquated classifications based mainly on mineralogical 
facies.” On the contrary I believe that Mr Dollfus and I are in 
perfect accord in regard to the principles of classification. We 
both consider palaeontology and stratigraphy to be the true guides, 
and we only differ because we interpret the teaching of these guides 
in different ways. A, J. JUKES- BROWNE. 
ETRURIA, TORQUAY. 
