GEOLOGICAL SOCIETY OF PENNSYLVANIA, 



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in the form of burnt or charred wood, not bituminous, 

 but having their ligneous fibres preserved. 



We have moreover a distinguishing evidence of the 

 more recent character of these deposits than those of 

 the Richmond coal field, in the friable open texture of 

 the grits, which are no more crystalline than ordinary- 

 oolites, whereas the rocks of Richmond are compact, 

 frequently subcrystalline and porphyritic. 



It must be observed that all the genera to which we 

 have assigned the fossil plants of Fredericksburg occur 

 in the oolitic groupe of Europe. For this fact we have 

 the testimony of M. A. Brongniart, Saussure, Phillips, 

 Murchison, De la Beche, and many others. These 

 genera have also been found, according to M. Elie de 

 Beaumont, to a certain degree associated with belemnites 

 and other fossils of the lias, inasmuch as those fossils are 

 imbedded both above and beneath them. But we have 

 seen no traces of algse, cycadese, or of conifera, all of 

 which orders occur sparingly in the oolitic series of 

 Europe. 



In the absence of further direct and affirmative evi- 

 dence respecting the Fredericksburg secondary deposit, 

 it will perhaps be convenient to retain for the present 

 the local appellation we have conferred upon it. 



