ANNIVERSARY ADDRESS OF THE PRESIDENT. CXI 



to the Geological Society of France, and a statement of the advance 

 of our Geological Survey, could so long have occupied our attention. 

 The political events of the past year have, no doubt, interrupted geo- 

 logical investigations in many parts of Europe, yet even under this 

 disadvantage it is gratifying to find how much has been accomplished 

 in European geology, while steady advances have been made in our 

 knowledge of America, especially of its northern portions, and of 

 various other parts of the world. 



We cannot omit to call your attention to the publication, during 

 the year, of a second volume of the ' Explication de la Carte Geolo- 

 gique de la France,' by MM. Dufrenoy and Elie de Beaumont * ; an 

 important work, more especially as regards a right knowledge of the 

 geological structure of France. It is remarked in the introduction 

 to this volume that the study of the relations existing between the 

 topography and the nature of the rocks had induced the authors to 

 give detailed descriptions of the successive zones forming the outcrop 

 of the different divisions of the Trias and the Jurassic limestone. 

 They therefore have made known the regular course of these divi- 

 sions in the basin of the north of France by examples taken at short 

 distances from each other, and they have adopted the same method 

 for the south of France in order to show the differences presented by 

 the same deposits either in their lithological characters or in the na- 

 ture of the fossils disseminated among them. These details also 

 enabled them to render full justice to the labours which have either 

 preceded or followed the publication of the geological map of France. 

 The work is accompanied by 1 05 illustrative diagrams, and, in addi- 

 tion to the scientific detail, notices are given of the useful mineral 

 substances found in, or forming part of, the rocks described. It is 

 announced that the third volume will contain an account of the re- 

 mainder of the sedimentary rocks which have been only slightly dis- 

 turbed since their deposit, and that there will be a volume dedicated 

 to the description and figures of shells characteristic of the different 

 fossiliferous deposits of France. 



The trias, consisting of the gres bigarre, the muschelkalk, and the 

 wz«r/ze5 m.see5, is described as occurring (1) around the Vosges, parti- 

 cularly on the plains of the ancient Lorraine ; (2) on the flanks of 

 the mountains of the Charollais, in the departments of the Cote d'Or, 

 of the Saone and Loire, and of the Rhone ; (3) on the northern foot 

 of the mountains of Central France, in the departments of the Nievre, 

 of the Allier, of the Cher, and of the Indre ; (4) on the slope of the 

 hills of the Bocage, in the departments of Calvados and La Manche ; 

 (5) on the southern side of the central mass of France, in the depart- 

 ments of the Lot, the Aveyron, the Tarn and Garonne, the Tarn, and 

 the Herault ; and (6) on the flanks of the Montagues des Maures, in 

 the department of the Var. Some other localities in disturbed di- 

 stricts, such as the Pyrenees and Jura, are to be separately noticed. 



A small map is given, showing the outcrop-course of the Jurassic 

 rocks, the divisions of which, it is remarked, present the great ad- 

 vantage of being nearly continuously traceable from one end to the 

 * A thick quarto volume containing 813 pages. 



