148 PROFESSOR ANSTED, ON THE 



beds several feet in thickness, but not extending far in any direction ; 

 and these beds alternate usually with thin marls, which are often quite 

 white in consequence of the enormous abundance of crushed shells 

 belonging to land and fresh-water species, which often completely hide the 

 marl, and cover the surface of the lignite. 



SECTION I. ACROSS THE GREAT VALLEY OF SWITZERLAND. 



Level oj Lake of Gtnna. 



Level of the Sea. scale of dUlancet i of an inch i 



.... 7 , . i to a mile, 



of heights .} inch > 



From the annexed section some idea may be formed of the relative 

 positions and magnitude of the three lines of elevation already alluded to 

 as existing in the Molasse, and the place which the two beds of lignite 

 occupy : the dips are principally towards the East, and more or less 

 with a Southerly tendency, but the amount varies, and is, I think, 

 generally most considerable in the neighbourhood of the High Alps, 

 towards which the strata incline. 



I have now only to add a few words more on this part of my subject ; 

 viz. to point out, so far as 1 am able, what remains to be done for the 

 more complete illustration of the Tertiary Geology of Switzerland. 



In the first place, there occurs a question of great interest, and one 

 which requires, probably, very accurate research to determine: viz. 

 whether the lines of elevation to which I have directed attention were 

 really caused by upheaving forces, or merely by denudation — whether, 

 in a word, there are lines of fault, or anticlinal axes, corresponding to 

 the lines of elevation. In the next place, it would be extremely interesting 

 to identify, if possible, the two beds of lignite — a task which I was 

 unable to perform ; and lastly, it is possible that, barren as the sandstone 

 is of fossils, some may yet be discovered, by which we may declare 

 with certainty the actual geological age of the formation. With regard 

 to this latter point, I shall have a few words to add at the conclusion of 



