Revieics — Barrois on the Upper Cretaceous Beds. 515 



From the facts described in the preceding chapters of the work, 

 Dr. Barrois concludes that the English Chalk is composed of a cer- 

 tain n amber of zones, equally characterized both stratigraphically 

 and palasontologically, as shown in the table given at pp. 222-23, 

 and here reproduced (see Table, pp. 516-517), and that these sub- 

 divisions can be compared with those established for the Chalk of 

 the basin of Paris and the North-west of Germany. All this 

 region formed one climatic zone, and has been subjected to the 

 same general movements of the surface, both before, during, and 

 after the Cretaceous epoch. The movements anterior to this 

 epoch have bearings with the formation of the Cretaceous basins, 

 the posterior movements have determined the foldings of the 

 strata; and that these foldings, both in England and on the Con- 

 tinent, have a relation in direction to much earlier dislocations, 

 showing that the same movements of the surface have been re- 

 peated at long intervals.^ Further, these foldings have consider- 

 ably influenced the effects of posterior denudation ; the rivers of 

 the north of the basin of Paris flow in the great Cretaceous undu- 

 lations, as those in the basin of Hampshire at the Quaternary 

 epoch , the rivers in the South of England flow in the transverse 

 dislocations. 



Although some of the conclusions of Dr. Barrois on the corre- 

 lations of certain divisions of the Cretaceous rocks may not be 

 entirely accepted by his brother geologists in England, yet they 

 must admire the industry of the young French geologist, necessary 

 for the production of this memoir, and the careful and philosophic 

 spirit with which the subject is treated, the result not only of his own 

 researches, but from a full acquaintance with the literature of the 

 subject, to which he constantly refers and quotes from throughout his 

 paper, and in which some of his previous opinions are modified ; for 

 this, although the most extensive, is not his first notice of the Chalk 

 of England.^ 



We have had personal opportunities of seeing the careful and 

 systematic manner with which Dt. Barrois observes and collects in 

 the field, the- result not only of a thorough interest in his work, but 

 possibly also of a previous good training, and in this respect he is a 

 worthy pupil of an equally worthy and energetic teacher, — Prof. J. 

 Gosselet, to whom this memoir is dedicated,, and which must form a 

 necessary addition to the library of every student of Cretaceous 

 Geology. 



1 Page 118. " Ondulations de la Craie dans le sud d'Angleterre," Ann. Soc. 

 Geol. du Nord, t, ii. p. 85. Dr. Barrois has explained the bearings of these undu- 

 lations of the Chalk on the proposed Channel Tunnel in two letters, published in the 

 Eevue Scientifique, April, May, 1875. See also M. Hebert, Bull. Soc. Geol. France, 

 2 ser. t. xxix. p. 583; ibid. 3 ser. t. iii. p. 512. 



2 Description geologique de la Craie de I'lle de Wight, Paris, lS7o. See also 

 Ann. de la Soc. Greologique du Nord, Lille, 1874, 1875. 



