238 
THE CRETACEOUS RO'CKS OF BRITAIN, 
Ft. 
Zone of Belemnites plenus.— At the top is a bed of pale green 
marl 2 feet thick ; the chalk below is at first greyish, but 
passes down into hard whitish chalk - - - - - 66 
Chalk of Ammonites rotomagensis.— Compact grey marly 
chalk - -- -- -- -- --66 
Chalk of Ammonites varians.-Ch.dAk. marl, more or less 
argillaceous, with a nodular bed at the base full of Plocos- 
cyphia mceandrina and PI. fenestrata - - - - 50 
Chloritic Marl ( zone of Ammonites laticlavius). — The upper 
part is a sandy chalk marl with green grains, the lower part 
a dark green marly sand, full of phosphatic nodules (many 
fossils, some phosphatic, some not) - - - - - 10 
192 
It will be seen that this succession corresponds very closely with 
that of Dover (see p. 37), but is somewhat differently divided. 
The Chloritic Marl or zone of Am. laticlavius is identical with our 
zone of Stauronema Carteri. The “ Chalk of Am. varians ” corre¬ 
sponds with Beds 2, 3, 4, 5 of our Dover section. The “ Chalk of 
Ammonites rotomagensis ” appears from the thickness assigned to it 
to correspond with our Beds 6 and 7, but as Dr. Barrois records Am. 
varians from it, some of our Bed 5 may also be included in it. The 
following fossils are mentioned as occurring in this 66 feet: — 
Ammonites varians. 
„ rotomagensis. 
„ Austeni. 
Ostrea vesicularis. 
Pecten orbicularis. 
Plicatula inflata. 
Inoceramus virgatus, (=striatus). 
Rhynchonella mantelliana. 
Serpula umbonata. 
Holaster subglobosus. 
Hemiaster Morrisii. 
„ Griepenkerli. 
Cidaris vesiculosa. 
Echinocyphus difficilis. 
Peltastes clathratus. 
Pseudodiadema ornatum. 
„ pseudo-ornatum 
,, Michelini. 
,, variolare. 
The description of the highest subdivision called by Prof. Barrois 
the zone of Belemnites plenus answers exactly to our Beds 8 and 9. 
It appears, however, to be much more fossiliferous on the French 
side, and M. Chellonneix has given a long list of fossils obtained 
from the whitish chalk by Dr. Bobbe and himself. Among them 
are the following : — 
Cerithium luscliitzianum. 
Solarium Gosseleti. 
Pecten orbicularis. 
Inoceramus striatus. 
Exogyra haliotoidea. 
Ostrea canaliculata. 
Terebratula semiglobosa. 
,, squamosa. 
Kingena lima. 
Rhynchonella grasiana. 
„ Martini. 
,, mantelliana. 
Terebratulina rigida. 
Teredo amphisbaena. 
Vermicularia umbonata. 
Hemiaster bufo. 
Micrabacia coronula. 
Onchotrochus serpentinus. 
This assemblage is such as might be found in our Chalk Marl, 
and we cannot help expressing some doubt as to their having all 
come from the higher beds. We give the list because Prof. Barrois 
has quoted it, but we think it requires confirmation. 
