THE CARBONIFEROUS SYSTI.M 245 



as their facies of the system is almost wholly marine. The nomen- 

 clature will therefore be as follows : 



Englaml. Prance. Russia. 



Westphalian. Stephanian. Uralian. 



Avonian. Westphalian. Moscovian. 



Dinantiaii. Dinantian. 



In England, France, and Belgium, as well as in Russia, the 

 nian consists almost entirely of marine deposits, and in most 

 districts it is mainly composed of limestone. In Germany, on the 

 other hand, it consists of carbonaceous shales with beds of sandstone 

 and has long been known as the Culm. The Westphalian is 

 everywhere (except in Russia) a varied succession of sandstones, 

 shales, clays, and coal-seams, which seem to have been deposited on 

 the borders of a sinking laud, in deltas and lagoons, where the 

 water was sometimes saline and sometimes brackish or fresh. The 

 Stephanian is also a Coal-Measure Series of similar character in 

 the west of Europe, but passes eastward into the marine Uralian 

 of Russia. 



As each of these great series has in some places a thickness of 

 9000 to 10,000 feet, and as the fauna and flora of each differs con- 

 siderably from that of the others, it will be convenient to describe 

 them separately and in succession. 



I. THE AVONIAN SERIES 

 A. LIFE or THE EPOCH 



Plants are naturally not common fossils in marine deposits, so 

 that the number known from this series is not large. The flora is 

 almost the same as that of the Upper Devonian, and the following 

 are the principal genera : 



Archwocalamites ( = Sornia), Cheirostrobus, Kphenopteris, (S. affinis 

 and S. elegans\ Adiantites, Rhacopteris, Cardiopteris, Heterangium, 

 Lepidodendron, Lepidophloios, and Pitys. 



The Dinantian fauna is a rich one, both in genera and species. 

 The following is a brief account of it, new generic appearances 

 being marked with an asterisk. 



Hydrozoa Chcetetes. 



Foraminifera. These become very abundant in the rocks 

 of this period and contribute largely to the formation of some of 

 the limestones, the principal genera being Saccammina, Endothyra, 

 Fnxiilina, Trochammina, Valvulina, and Lagena. 



Anthozoa. Of corals the most common genera are Aulo- 



