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interfered with its assuming this structure on a minuter scale. 

 It may be given, indeed, as an ahnost universal rule, applicable 

 to the whole range of the Appalachian rocks, that wherever this 

 cleavage prevails extensively, it shows itself in the sandstones on 

 a scale commensurate, as to distance between the planes, with the 

 thickness of their beds and their coarse arenaceous character. 

 For even in these coarser strata, though the divisional surfaces are 

 three feet and more asunder, they preserve their regularity and 

 constancy of direction, and their parallelism to the slaty cleavage 

 of the argillaceous parts of the series. 



ORGANIC REMAINS. 



The relics of organic life imbedded in this great sandstone 

 formation are singularly few, if we except two or three interesting 

 species of marine vegetation. These belong to the tribe of 

 extinct seaweeds called fucoides. The principal varieties are 

 the fucoides Brongniartii, and the fucoides Alleghaniensis. The 

 cliffs in the middle of the gorge of the Delaware Water Gap 

 exhibit fine specimens of the former, covering with a beautiful 

 reticulation the faces of the white sandstone beds over many 

 square yards of surface. The latter species abounds where the 

 formation alternates in its upper layers with the lower beds of 

 the overlying red sandstone. Properly considered, it is a fossil 

 more strictly characteristic of the latter rock, being confined in 

 this alternation of the formations chiefly to the red layers. 

 Hitherto I have discovered but one fossil of the animal kingdom 

 in the rock of the Kittatinny Mountain. 



This is a small species of terebratula of a nearly spheroidal 

 form, found as yet in few places, and chiefly in the uppermost 

 beds of fine-grained white sandstone. The turbulent condition of 

 the currents in the earlier periods of the general deposit, would 

 seem to have interfered with the multiplication of animated races 

 on the sandy bed of that ancient unquiet sea. 



ECONOMICAL GEOLOGY. 



The white and light gray sandstones of this formation seem, 

 from their durability and the regularity of their stratification, to 



