250 



Scientific Geology. 



in the transition series, (terrains hemilysiens,) which being peculiar 

 to that class, differs essentially from those found in the later rocks."* 

 And we have seen that Adolphe Brongniart regards as belonging to 

 the first period of vegetation, all the rocks below the new red sand- 

 stone. De la Beche does, indeed, mention that the crustaceous ani- 

 mal Calymene Blumenbachii has been found at Newport, United 

 States : meaning, probably, Newport, Rhode Island. And were this 

 the fact, it would be important in determining the question as to the 

 transition character of the rocks in question ; since, according to Al. 

 Brongniart, the trilobites "pertain exclusively to the hemilysian 

 rocks." But on looking into the Tableau des Terrains, &c. of this 

 writer, (p. 429,) from whence De la Beche must have derived his 

 information, we rind that he speaks of Newport as near Utica ; (Leb- 

 anon sur V Ohio, et Newport, pres Utica, Amer. Sept.) a misprint, 

 perhaps, for Lockport. Besides, he describes the fossil as from lime- 

 stone, a rock which at Newport contains no fossils. 



After these explanations, I trust it will be obvious that it is not my 

 object to identify the rocks in question, with the graywacke of Eu- 

 rope : but simply to describe them as they are. And though it would 

 be gratifying to find that all our fragmentary and fossiliferous rocks 

 correspond exactly with those of other continents, yet I am more and 

 more inclined to doubt whether such identity can ever be made out. 

 For if, as we have every reason to believe, these rocks were deposited 

 in the beds of former seas and lakes, as similar ones are now form- 

 ing, why should we not expect as much diversity in their composition 

 and organic remains, in different quarters of the globe, as we should 

 find in the sandstones, conglomerates, and limestones, which would 

 result from the consolidation and elevation of the sand, gravel, and 

 calcareous matter, that constitutes the bottom of existing seas, estua- 

 ries, and lakes ? Should such a consolidation and elevation take 

 place, we might perhaps find resemblances enough between distant 

 strata to prove them of contemporaneous origin, and the result of the 

 same general causes. Still, we should undoubtedly find much in 

 each group of strata, of a sui generis character, and not a few groups 

 entirely peculiar and independant ; though produced during the same 

 geological epoch. Hence, then, is it not best to direct one's chief 

 efforts to give a correct description of our rocks, rather than spend 

 the time in efforts to identify them with European formations ? Many 



* Tableau des Terrains, p. 29L 



