LOWER CHALK—NORTH-EAST OF FRANCE. 
24 *7 
We think it is just the same in the eastern part of France, and 
that the glauconitic marl which he refers to the zone of Am. lati¬ 
clavius is merely a part of Prof. Parrots’ zone of Hoi. subglobosus. 
Without personal examination of the sections we are not prepared 
to say what part. 
We come next to the Sables de la Hardoye, and here, again, we 
are met by a want of evidence. Professor Barrois only collected 
nine species of fossils in these sands in the whole of its range, and 
none of these are characteristic or critical species ; not one of them 
is a Ceplialopod. It is true that three of them do not in England 
range above the Upper Greensand ; these are Vermicularia con- 
cava, Verm, polygonalis, and an Exogyra like E. digitata. But 
these are forms which would be very likely to survive in places 
where the local conditions were suitable, after their extinction in 
the areas of deeper water. 
It has been mentioned that Professor de Lapparent considers 
that the greensand of Ste. Menehould replaces a part of the Chalk 
Marl of Vitry, and as this greensand is believed by Prof. Barrois 
to be the continuation of his Sables de la Hardoye, we see no reason 
why the whole of this sand, as well as the Sable d’Avesnes, should 
not be regarded as representing a portion of the zone of Am. various. 
Finally, we come to the Marne de Givron, which is in some respects 
the most puzzling deposit of all. According to Prof. Barrois it forms 
the lower part of his Pecten asper zone, and might be compared 
with the Chert Beds of Wiltshire, while for Professor de Lapparent 
it replaces the upper part of the Gaize. So far as the stratigraphical 
evidence is concerned, one or other of these views would certainly 
seem the most natural interpretation of the facts, but when we 
examine the fauna of the Marne de Givron, we shall see it cannot 
belong to the zone of Ammonites rostratus. The characteristic 
fossils of that zone are absent, and the Ammonites which do occur 
are falcatus, various, and Goupei, all characteristic of the true 
Cenomanian. If the fauna were considered apart from any strati¬ 
graphical bias, it would undoubtedly suggest correlation with the 
zone of Ammonites various—i.e., with the Chalk Marl of England, 
and with the craie glaucouieuse of Havre and Rouen. I admit, 
however, that it can also be compared with that of the Rye 
Hill sand, (or subzone of Catopygus columbarius ), and conse¬ 
quently Professor Barrois may be right in placing it below the 
horizon of Am. laticlavius. 
The following is a list of the fossils recorded by Dr. Barrois from 
the three horizons which he denominates (1) Marne de Givron, 
(2) Sables de la Hardoye, and (3) zone a VAmmonites laticlavius; 
in the Departments of Aisne, Ardennes, and Marne : — 
