PRELIMINARY REMARKS. 



In the descending order we now arrive at that extensive and important series of rocks 

 to which the term Carboniferous System has been so emphatically applied ; a period 

 unequalled for the extraordinary luxuriance of a flora, which in its present fossil 

 condition has proved a source of so much wealth and prosperity to this and other nations : 

 but it is not only the vegetation of its land that has proved so remarkable, the inhabitants 

 of its waters were perhaps almost equally so ; and in every respect deserving of the most 

 careful and complete investigation. The system occupies a considerable area in England, 

 Scotland, and Ireland, as may be perceived by a glance at any geological map. 1 It is 



1 We extract the following passage from Mr. Marcou's excellent Memoir on the American Carboniferous 

 Deposits (' Bulletin de la Soc. Geol. de France,' vol. xii, 2d series, p. 844) : 



" The Carboniferous period is composed of a series of rocks, the importance of which, whether it be con- 

 sidered in the scientific, industrial, or commercial point of view, is neither equalled nor even attained 

 by any of the other sedimentary deposits. In a scientific point of view the Carboniferous group 

 presents the most extended geognostic horizon, of which the characters are constant over all the surface 

 of our terrestrial globe. In Europe, in Asia, in Africa, in the two Americas, as well as in Australia, we 

 meet with the same rocks, and often also with the same fossils ; and one is at a loss to know which 

 should be most admired, this consistency in the lithological characters of its strata, or the presence 

 of the same fossils buried in contemporaneous beds, and often situated at the antipodes. From the 

 glacial zone of Spitzberg, the Bear, and Melville Islands, to Australia, Tasmania, and New Zealand, 

 the Carboniferous strata form islands, mountains, table-lands, plains, and even half continents, where 

 the identity and unity of the lithological and palseontological characters exhibit the surest marks of 

 recognition and the most certain horizon that can be found in geological investigations. . . . 

 " The Carboniferous deposits of America may be divided into an upper and lower deposit : 

 " a. Upper Carboniferous, or Coal measures, above the mountain limestone, is composed of a series of 

 beds of sandstone and argillaceous schists, containing beds of coal, and which constitutes the 

 Coal formation properly so termed. In America it contains no Brachiopoda. 

 " b. The Lower Carboniferous, of which the general character is, so to say, universal; since we observe 

 that it presents well-stratified beds of a hard grayish limestone, replete with numerous marine 

 fossils, similarly found in Europe, America, and Australia. In America it contains Athyris 

 Roissyi,planosulcata ; Sp. striata, lineata ; the Orthis crenistria, Michelini ; Prod, semireticulatus, 

 Cora, Flemingii, costatus, scabriculus, pixidiformis, pustulosus, and others." 



1 



