THE PKE-ADAM1TE EARTH. 



The stratification from the superior limit of the Azoic rocks 

 upon which the Palaeozoic formation rests, to the upper limit 

 Fig. 141. of the Carboniferous stage, delineated in 



section by Sir R. Murchison, is shown in 

 tig. 141, as it is presented on the surface of the 

 earth in strata variously inclined. The five 

 divisions into which the whole formation is 

 resolved are denominated, proceeding from the 

 lowest upwards, the Cambrian (sometimes 

 called the Lower Silurian), the Silurian, the 

 Devonian, the Carboniferous, and the Permian. 



255. In the geological map of England by 

 Sir K. Murchison, the stages succeed each 

 other regularly throughout Wales and the 

 western parts of England, where they appear 

 in some places in concordant, and in others in 



I discordant, stratification. They are traced 

 scarcely less distinctly in Germany. The same 

 regular succession of five superposed stages 

 is seen in Russia and in Sweden from west 

 to east, and extending in the same order 

 to Central Russia. Along the slopes of the 

 Ural, the stages being tilted upwards, are 

 found, as may be expected, in a contrary order, 

 the lowest being the most eastward, and the 



"" uppermost the most westward. M. D'Orbigny 

 found the same regularity in South America. 



256. The complete distinction of the stages, 

 and the geological evidence of the convulsions 



' by which they were rendered separate and 

 independent, are found in the fact that in some 

 places particular stages are absent. Thus we 

 see in the United States the three first stages 

 only existing in concordant stratification for 



hundreds of leagues, the lowest being absent. 

 The same is observable in the department of 

 Sarthe and the Manche in France. Elsewhere 

 the Carboniferous and Devonian stages alone 

 are found; as, for example, in the Pas de Calais, 

 and in certain parts of Spain, or one only of 

 them, as in Norway, Sweden, Russia, France, 

 and some other countries. 



257. Upon a general view of the Pal&ozoic 

 formation and its component stages, there is 

 evidence, founded on the indications which 



- *y 



