258 



LOWER MIOCENE STRATA, SWITZERLAND. 



[Ch. XV. 



Middle or Marine Molasse [Upper Miocene) of Switzerland. — It 

 was before stated that the Miocene formation of Switzerland con- 

 sisted of, 1st, the upper freshwater molasse, comprising the lacustrine 

 marls of (Eningen ; 2 dry, the marine molasse, corresponding in age to 

 the faluns of Touraine ; and 3dly, the lower freshwater molasse. 

 Some of the beds of the marine or middle series reach a height of 

 2470 feet above the sea, A large number of the shells are common 

 to the faluns of Touraine, the Vienna basin, and other Upper Miocene 

 localities. The terrestrial plants play a subordinate part in the fossil- 

 iferous beds, yet more than 90 of them are enumerated by Heer as 

 belonging to this falunian division, and of these more than half are 

 common to subjacent Lower Miocene beds, while a proportion of 

 about 45 in a hundred are common to the overlying (Eningen flora. 

 Twenty-six of the 92 species are peculiar. 



Lower Molasse [Lower Miocene) of Siuitzerland. — Next in descend- 

 ing order comes the Lower Molasse, almost entirely of freshwater ori- 

 gin, of which the Upper division contains 211 species of plants and 

 the Lower no less than 336 species. The first of these two is called 

 in Heer's work the " Mayencien," it being supposed to agree in age 

 with the strata of the Mayence basin already described, while the 

 lower division is called the " Aquitanien," as corresponding with some 

 of the older Miocene beds of the South of France. But the fossil 

 shells by which these comparisons have been made appear to me to 

 be at present too few in number to enable us to place much reliance 

 on such identifications. The superposition, however, of the Molasse 

 called " Mayencien "" to the lower beds called " Aquitanien," which 

 last are well seen on the borders of the Lake of Geneva, is perfectly 

 clear. 



To the upper group belong the sandy marls of Eriz, in the Canton 

 of Berne, in which there are 68 species of plants, half of them com- 

 mon to the (Eningen strata. Among the North American forms in 

 this locality the tulip tree may be mentioned, a species very closely 

 allied to the Liriodendron tulipifera, L. 



Fig. 194. 



Liriodendron Procaccinii, Unger. 

 fleer, pi. 108, fig. 6. Eriz. Lower Miocene. 



Woodwardia Eossneriana, Unger. 

 Heer, pi. 5. Eriz. Lower Miocene. 

 a. Part of a branch, b. Part of a leaf mag- 

 nified, showing the position of the sori. 



