CATSKILL GROUP. 189 



why the strongest hopes have been entertained of finding coal where they exist, the great fact 

 of position and more important associates of the coal beds not having been attended to. In- 

 stances are but too frequent where explorations for coal have been undertaken, which have 

 been attended with much anxiety of mind, and have resulted in nothing better than a waste of 

 time and loss of money. 



The Catskill group is the immediate predecessor, and the base therefore of the Coal for- 

 mation. On it the latter rests, when they coexist in the same locality. This fact gives a 

 high interest to the Catskill group, from the great importance of the coal, and the certainty 

 that all of it is the product of vegetation, with the insignificant exceptions of animal origin ; 

 and every plant which preexisted to that era is of importance also. Both were the pre- 

 cursors of one of the most extraordinary periods of the world's history, in which the sur- 

 face of the earth was covered, as if by enchantment, with a luxuriant vegetation, and wholly 

 of a peculiar Flora. During the continuance of that period, vast stores of coal were formed, 

 the daily consumption of which now adds to man's production, and the increase of the arts ; 

 and with every advance of the latter, a proportionate advance of higher powers of the mind 

 also takes place. To those who connect effects with their causes, every discovery of a plant 

 in any rock which preceded those of the coal era is of interest, as adding a valuable fact 

 towards the final solution of that remarkable era, an era like which none other existed either 

 before or since. Entertaining this opinion, no opportunity was lost in adding to the number 

 of facts knoven. 



The coal was not the product of a transient period ; for during its day the carboniferous 

 limestone was formed, which in many countries, from its thickness and great extent, is an 

 important member of it. It abounds in marine fossil shells, which are as characteristic 

 of it as those of the Chemung, the Hamilton and the Trenton masses are of their respective 

 rocks. Where this limestone does not exist, shells are extremely rare, which is the case with 

 the whole of the rock associated with the Pennsylvania coal, upon its north and east border, 

 showing in this respect, and which is also the fact in other countries, an accordance with the 

 Catskill group ; the conditions required for marine fossils having been but very partially com- 

 phed with during the whole period that their materials were being deposited, with the excep- 

 tion of the carboniferous hmestone before mentioned. 



Besides the very common plants which have no determinate markings upon their surface, 

 others have been found in this group, some of which are in the State Collection. 



