THE TRIASSIC PERIOD. 205 
extraordinary series of fossiliferous beds, replete with marine 
fossils. Sir Charles Lyell gives the following table of these 
remarkable deposits : — 
Strata below the Lias in the Austrian Alps, in descending order. 
Grey and black limestone, with calcareous 
marls having a thickness of about 50 
feet. Among the fossils, Brachiopoda 
1. Koessen beds. very numerous ; some few species com- 
(Synonyms, Upper St mon to the genuine Lias ; many pecu- 
Cassian beds of Escher liar.  Avicula contorta, Pecten Valo- 
and Merian.) niensis, Cardium Rheticum, Avicula 
inequivaluis, Spirifer Myiinsteri, Dav. 
Strata containing the above fossils al- 
ternate with the Dachstein beds, lying 
next below. 
White or greyish limestone, often in beds 
three or four feet thick. Total thick- 
ness of the formation above 2000 feet. 
Upper part fossiliferous, with some 
: strata composed of corals (Lithoden- 
2. Dachstein beds. dron.) rowek portion Sa fossils. 
Among the characteristic shells are /e- 
micardium. Wulfeni, Megalodon trigueter, 
and other large bivalves. 
Red, pink, or white marbles, from 800 to 
1000 feet in thickness, containing more 
than 800 species of marine fossils, for 
3. Hallstadt beds the most part mollusca. Many species 
(or St Cassian). of Orthoceras. True Ammonites, besides 
Ceratites and Gontatites, Belemnites (rare), 
Porcellia, Pleurotomaria, Trochus, Mono- 
tis salinaria, &c. 
A. Black and grey lime- 
4. A. Guttenstein beds. stone 150 feet thick, al- Among the fossils 
B. Werfen beds, base of ternating with the un- are Ceratites 
Upper Trias ? derlying Werfen beds. | oerenu, 20" 
é - : 
Lower Trias of some | 8. Red and green shale Soe. Nabveliz 
geologists. and sandstone, with costata, &c. 
salt and gypsum. 
In the United States, rocks of Triassic age occur in several 
areas between the Appalachians and the Atlantic seaboard ; 
but they show no such triple division as in Germany, and their 
exact place in the system is uncertain. The rocks of these 
areas consist of red sandstones, sometimes shaly or conglomer- 
atic, occasionally with beds of impure limestone. Other more 
extensive areas where Triassic rocks appear at the surface, are 
found west of the Mississippi, on the slopes of the Rocky Moun- 
tains, where the beds consist of sandstones and gypsiferous 
