174 MESSES. A. J. JUKES-BROWNE AND W. HILL : [May 1 896, 



of the Cenomanian at Rouen. "We have not seen this bed, but it is 

 described as a glauconitic chalk containing phosphatic nodules and 

 many fossils, among which Scaphites cequaUs, Baculites baculoides, 

 Ammonites navicularis, and A. rotomagensis are common. It is 

 remarkable that phosphatic fossils of these species abound in the 

 bed which overlies No. 12 between Axmouth and Lyme Eegis. 

 Some of them are also common in Bed 7 of St. Jouin. 



These facts suggest the idea that beds comparable to the upper 

 part of the French Cenomanian, and, like it, containing many phos- 

 phatic nodules and casts of fossils, were originally deposited in the 

 Devon area, but were afterwards destroyed by the action of currents, 

 and nothing left of them except the hard phosphatic fossils, with 

 grains of quartz and glauconite, to be embedded as remanie material 

 in the beds which overlie the zone of Ammonites Mantelli. 



Having thus summarized the opinions which we have been led 

 to form from an examination of the rocks and their contents in the 

 West of England and France, we shall conclude by discussing 

 the view which is generally held in the latter country regarding the 

 correlation of the several parts of the two series. 



It is on the Cenomanian of Havre that we must concentrate our 

 attention, because when its relative age is settled that of the inland 

 departments will follow as a matter of course. No one now is 

 likely to recur to the view of Prof. Hebert that the Cenomanian 

 sands of the Sarthe are newer than the Craie de Rouen, and that 

 no representative of them exists in Normandy or England. 



The view current at the present time among French geologists is 

 that the lower part of the Cenomanian of Havre, as denned by 

 M. Lennier and ourselves, corresponds with the upper part of our 

 Upper Greensand — with so much of it, in fact, as is included by 

 Dr. Barrois in his zone of Pecten asper. We cannot find, however, 

 that anyone has yet attempted to indicate how much of the Craie 

 glauconieuse is equivalent to the English Lower Chalk and how 

 much to the zone of P. asper. 



It is true that Dr. Barrois has expressed his belief that his zone 

 of Ammonites laticlavius (our Chloritic Marl) in the East of France 

 corresponds with 4 le banc Rotomagien classique de Rouen,' 1 but 

 in answer to our enquiries he informs us that he has no personal 

 acquaintance with the Havre or Rouen sections ; that the fossils 

 mentioned in his note were collected for him, and were said to come 

 from the ' Craie de Rouen ' ; that he had no assurance that they came 

 from Rouen itself; that some of them are preserved in whitish 

 phosphate and some in glauconitic material, and that they may be 

 * un melange.' This being so, it is quite possible, as he admits, that 

 some of them were obtained on the coast, and may have come from 

 the very bed which we identify with the Chloritic Marl ; in any 

 case, we feel sure that if Dr. Barrois had visited Havre after his 



1 ' Mem. sur le Terr. Cret. des Ardennes,' Ann. Soc. geol. Nord, vol. v. (1878) 

 p. 355. 



