Reviews — A. de Grossouvre on the Upper Chalk. 39 



than others, and it suffers as a whole from the fact that its component 

 parts have been printed off in successive years from 1895 to 1901. 

 The author states this in order to explain his omission to notice the 

 numerous publications on the Chalk which have appeared since 

 the earlier chapters of his monograph were printed off. Thus the 

 account of the Chalk of England and Ireland which forms Chapter v 

 is much behind the knowledge of the day ; it is short and taken 

 almost entirely from Prof. Barrels' "Eecherches" (published in 1876), 

 which was excellent at that date, but has since been corrected and 

 improved upon in many particulars. A great thickness is attributed 

 to the zone of Marsupites, while that of Actinocamax quadratus is said 

 to be little developed in England, the fact being that the greater 

 part of Prof. Barrels' zone of Marsupites is really referable to the 

 zone of Actinocamax quadratus. 



The Chalk of France (i.e. the Turonian and Senonian stages) is 

 described in considerable detail, separate chapters being given to 

 the following areas : the Paris Basin, Hainault and Limbourg, 

 Touraiue, Aquitaine, the Pyrenees, the valley of the Rhone, Provence, 

 and the Western Alps. The chapter on the Paris Basin, however, 

 does not include any adequate account of the Chalk of Normandy, 

 which indeed is hardly mentioned ; the reason of this is that since 

 Hebert's time no French geologist has examined the fine chalk cliffs 

 of Fecamp, St. Valerie, and Dieppe, that consequently the materials 

 for a zonal description of this area do not exist, and M. de Grossouvre 

 has been obliged to omit it from his purview. It is to be hoped 

 that he or some other capable geologist from France or England 

 will ere long make good this regrettable hiatus in our knowledge of 

 the Chalk of the Anglo-Parisian region. 



Other chapters deal with the Chalk (generally including the 

 Cenomanian) of the Central Alps, the Eastern Alps, Bavaria, 

 Bohemia, North Germany, Scandinavia, India, and the United States. 



Besides these there are four chapters which discuss questions of 

 general interest, and there is M. Lambert's essay on the genus 

 Micraster. Of these chapters I propose to give some brief review. 



Chapter i deals with stratigraphical methods and need not detain us 

 long. In it the author states his dissent from the method generally 

 employed in the correlation of strata, and especially of zones, 

 i.e., the method of comparing assemblages of characteristic fossils 

 including species of many different kinds of animals. This, he says, 

 has led to many errors, and after reviewing various animal groups 

 he concludes that Cephalopoda, and especially the Ammonoidea, are 

 the only group that provides us with a sufficiently rapid succession 

 of forms to furnish a dependable chronometric scale. " The method 

 to be followed should be the same as in the Jurassic System, to 

 begin with a chronometric scale based on the succession of Ammonite 

 faunas, then by a comparison of a sufficient number of sections in 

 different regions to establish the correlation of the beds in which 

 Cephalopoda do not occur." 



Chapter ii is entitled *'Des Conditions de depot de la Craie 

 Blanche." He refers to the antagonistic opinions which are held 



