ancient Gj/psum of the Alps. 87 



and form part of a series essentially posterior to the transi- 

 tion class. * 



* As the gypsum of Bex has been shewn to be secondary, and to fomi 

 part of the saliferous or new red sandstone series, and as M. Brochant de 

 Villiers mentions a loeality near Bex, where the superficial gypsum and 

 that of the latter place are seen to be almost continuous, there is very 

 good reason for supposing that all the superficial gypsums of the Alps 

 may be referred to the same class, and it is possible that many of the 

 others also may belong to the same epoch, particularly when it is recol- 

 lected how much confusion has existed relatively to the transition rocks 

 of this chain ; of this we have a striking instance in the rocks near Bex. 

 The difference between these gypsums and those of Germany con- 

 sidered as important, viz. one class resting on primitive and transition, 

 and the other on secondary rocks, can be of no consequence, any supe- 

 rior rock may rest upon an inferior one, the intermediate rocks being 

 wanting : thus for instance, the oolite formation of the Jura rests on 

 gneiss on the Rhine, at Lauffenburg, and lias on granite between 

 Rouvray and MaisonNeuve (department of the Cote d'Or, in France.) 

 (Trans.) 



