Ashtmriicr.] OiZ | Feb. 16, 



The series might he morn properly' divided into four memhers ; but as the 

 conghjuiL-rute beds tind coal-bearing strata of the middle member are 

 always found where coal beds have been discovered, the latter above the 

 former, I have preferred to consider these two foimations, which fca them- 

 selves are so distinct, as constituting one member. 



The upper member of the series is composed of coarse-grained, massive, 

 brownish-gray and gray sandstone, alternating with thinly bedded and 

 flaggy sandstones of the same color. Near the top there are a few beds of 

 red shale and sandstone ; and towards the bottom there are beds of black 

 slate containing floral impressions. 



The transition of the shales and sandstones of the lower member of No. 

 XI into this upper member of No. X is rather sudden. The bottom 

 of No. XI is rather argillaceous, Avhllc the top of No. X is very 

 sillcious ; the sandstones in the former (XI) are fine-grained, thinly bedded 

 and flaggy, while those in the latter (X) are coarse-grained, more 

 massive, and recur with fewer alternations of shale than in the 

 former case. The strata are thicker and the change from sandstone 

 to shale less frequent. The upper member of X generally forms the flank of 

 the ridge or mountain whose crest is formed by the lower part of the mid- 

 dle member. The eroded surface of the mountain being very nearly a 

 plane surface, although sloping of course at a pretty high angle, it is seldom 

 cut by streams running transversely to the strike, such as produce the gul- 

 lies which are so characteristic of that flank of a mountain of Medina 

 and Oneida (No, IV) formed by the Hudson shales ; in fact the drainage 

 is generally effected solely by the stream at the base of the mountain, 

 following it in a parallel direction 



The topography of the lower member of No. XI is very marked and 

 quite different from that just described. It generally presents itself as a 

 chain or .succession of little hills or knolls, containing the outcrop 

 of the limestone beds of XI, and separated by depressions through 

 which the small streams descending from the flank of the mountain of 

 XII, break just before they join the main stream of the vallej^ flowing 

 along the foot of the mountain of X. In the district lying east of the 

 Broad Top Mountain the place to look for the limestone beds is alongside 

 of and close to the principal stream, which therefore flows along 

 the eroded outcrops of the soft red shales belotr the limestone. This sug- 

 gests a third reason why the top of the Pocono or Vespertine sandstone 

 should not be considered the base of the mountain limestone. 



The middle member of X is subdivided into : 

 1. Coal-bearing strata. New River series. 



2-. Conglomerate and conglomeritic sandstone, characterized by false 

 bedding. 



The coal-bearing strata contain 19 seams of coal, with an average indi- 

 vidual thickness of one inch and a half Their thickness, if added to- 

 gether and combined with that of the numerous thinner seams and partings 



