FOURTH PALEOZOIC PERIOD. 



the globe, is proved by the existence of the same animal and 

 vegetable remains in this stage, in all localities to which geological 

 researches have been extended. 



278. The configuration of land and water in this period has 

 been determined on the principles already explained. The Hunds- 

 ruck system of Elie de Beaumont, directed W. 31 S., having 

 raised up the Silurian stage, increased the magnitude of the 

 islands which existed in the previous period, created new ones, 

 and gave to their coast its own prevailing direction. This will 

 appear by reference to the map (fig. 144) sketched by M. Elie de 

 Beaumont, showing the probable outlines of land and sea in 

 "Western Europe in the succeeding period. A tract of land arose 

 above the waters on the west of Frankfort, and another on the 

 S.W. of Strasbourg, which was united with the former continent. 

 The central plateau of France was extended to the Pyrenees. 

 The space included between the two islands of Brittany, which 

 previously existed, was now filled up, and being united with the 

 land round Cherbourg formed one continuous tract, which was 

 connected on the one side with the southern part of England, and 

 on the other with the Limousin by Poitiers. The land constitut- 

 ing the Scandinavian peninsula was also considerably increased. 

 Upon several parts of this tract the Silurian deposits have never 

 been since disturbed. 



279. The seas of this period covered Asia Minor, Spain, 

 Belgium, Germany, and Russia, as far as the Ural chain. The 

 land which now forms the shores of the Frozen Ocean was also 

 covered by these seas. In the east they extended from Asia 

 Minor to China ; in South America they covered all the tropical 

 regions of Peru, Bolivia, and Brazil, and probably extended as 

 far as the Falkland Islands, as is proved by the organic deposits 

 found in all these regions. In North America they covered all 

 the land which extends frqm Alabama to the state of New York. 

 They also covered New Holland and Yan Diemen's Land. Thus 

 it appears that the Devonian sea extended in the Southern Hemi- 

 sphere to 52 of latitude, and in the northern to the polar circle. 



FOURTH PAUEOZOIC TEKIOD. 



280. The convulsion which terminated the previous period 

 destroyed 59 generic animal forms, which never again reappeared 

 upon the earth, as well as 1198 species of Mollusca and Eadiata, 

 besides all the species of the other classes. After an interval of 

 tranquillity the earth was again repeopled, and once more clothed 

 with rich vegetation. The new animal kingdom called into 



47 



