532 HISTORY OF GEOLOGY AND PALAEONTOLOGY. 



They were shown to be followed by deposits of brackish- 

 water origin, Cerithia sands and clays charged with shells, 

 comprised by Suess under the general term of " Sarmatian 

 Stage." The strata of the Sarmatian Stage are extensively 

 distributed in the south of Europe, and the fauna had already 

 been described by De Marny and Eichwald. At the close of 

 the Sarmatian Stage, the deposits of the North-Alpine area 

 and the plains are essentially fresh-water deposits, comprising 

 the Congeria Clays, and the Belvedere pebble-beds, the latter 

 having been deposited from running water, probably by wide 

 river-courses pouring northward from the Alps. Suess com- 

 prised the fresh-water deposits under the name of " Pontic 

 Stage," and identified them as the equivalent of the Pliocene 

 formation. 



A few years earlier Suess had shown from the distribution 

 of the fossil terrestrial mammals in the various Tertiary de- 

 posits, that the older marine horizons, as well as the brackish- 

 water "Cerithia" sands, correspond in age with the Middle 

 Miocene* in France and Switzerland (Marine molasse, fresh- 

 water limestone of Oeningen, upper fresh-water molasse), while 

 the upper fresh-water formations of the Vienna basin contained 

 the fauna of the Upper Miocene deposits of Eppelsheim, 

 Cucuron, and Pikermi. The systematic divisions established 

 by Suess for the Austrian deposits have been verified by later 

 investigations, and only modified in minor particulars. 



The stratigraphical knowledge of the German Tertiary 

 deposits was late in developing. There were several diffi- 

 culties to contend with, the chief obstacle being the impos- 

 sibility of securing a complete section from which a definite 

 succession could be determined. This was the more un- 

 fortunate as the fossils that were found in the scattered 

 localities seldom permitted an exact identification with the 

 typical Eocene and Miocene forms known to the literature. 

 The German Tertiary deposits occur in three chief districts : 

 the North German plain, the Tertiary basin of the Rhineland, 

 and the Swabian-Bavarian plateau with the adjacent hilly 

 territory of the Alpine foreground. 



The neighbourhood of Mainz and Alzey first attracted the 

 interest of geologists on account of the wealth of fossils. Col- 

 lini and Faujas had described some of those in the eighteenth 

 century and in the beginning of the nineteenth century, and 

 Dechen, Oeynhausen, and A. Boue supplied a general de- 



