STRATIGRAPHICAL GEOLOGY. 471 



Wellenkalk 2. Lower Alpine limestone, dolomite, 



and rauchwacke, with Tere- 

 bratula vulgaris, Myophoria vul- 

 garis, etc. 



Bunter - - i. Red sandstone, Werfen shales with 

 Monotis C/arai, etc. 



Emmrich enumerated a larger number of fossils in the 

 Avicula contorta zone which had hitherto been referred to the 

 Liassic group, and in opposition to the views of Buch, Murchi- 

 son, Lill von Lilienbach, and Schafhautl, he pointed out the 

 strong affinities exhibited both by the Avicula beds and the 

 Lithodendron limestone with the St. Cassian series. 



In the Vorarlberg, Escher von der Linth, partially in col- 

 laboration with Merian, made the following sub-divisions of 

 the Wengen-Cassian group in the Triassic series : 



Megalodon dolomite (" Dachsteinkalk" 

 or "Main dolomite"). 



Upper St. Cassian strata with Gervillia 



inflata, Cardium Rhceticum, etc. 



St. Cassian Dolomite or middle St. Cassian (" Esino 



Group. "| Kalk "). 



Black marls with Bactryllium Schmidti 

 and limestone with Halobia Lommeli 

 (lower St. Cassian) plant sandstones 

 with Equisetum, Catamites, etc. 



In this sub division the upper St. Cassian strata of Escher 

 correspond to the "Gervillia" strata of Emmrich; and this 

 confusion of the St. Cassian marls with the Kossen marls 

 proved a frequent source of error in after years, and also led 

 to a consequent misinterpretation of the age of the limestone 

 or dolomite masses underlying the fossiliferous marls or 

 reposing upon them. Escher's Halobia Lommeli sub-division 

 is identical with the " Wengen " strata of Emmrich's South 

 Tyrol section. 



Important researches were made in the Trias of Lombardy 

 by Curioni (1855). He confirmed Escher's sub-divisions, 

 showed that the Halobia Lommeli strata and plant sandstones 

 rested upon Muschelkalk, and gave careful details regarding 

 the fossils and superposition of the lower and middle Triassic 



