206 



HISTORICAL PALEONTOLOGY. 



marls. The American Trias is chiefly remarkable for having 

 yielded the remains of a small Marsupial (Dromatheriuni}, and 

 numerous footprints, which have generally been referred to 

 Birds (Brontozoum), along .with the tracks of undoubted Rep- 

 tiles (Otozoum, Anisoptis, &c.) 



The subjoined section (fig. 139) expresses, in a diagram- 

 matic manner, the general sequence of the Triassic rocks when 

 fully developed, as, for example, in the Bavarian Alps : 



GENERALISED SECTION OF THE TRIASSIC ROCKS OF 

 CENTRAL EUROPE. 



Fig. 139- 



_L_L 



-L_L 



i r 



Upper Keuper (Kossen or 

 Rhaetic beds, and Dach- 

 stein beds). 



Middle Keuper (Hallstaclt 

 or St Cassian beds). 



Lower Keuper (Keuper 

 Sandstones proper). 



- -Muschelkalk. 



Bunter Sandstein. (Gutten- 

 stein and Werfen beds ?> 



With regard to the life of the Triassic period, we have to 



