840 FLORAL ZONES OF THE POTTSYILLE FORMATION. 



The most important I'tict, however, in connection with the trend of 

 the fault at Fishino- Creek Gap is the existence, at a short distance 

 west of this brown zone and alonu" the upper part of the mountain 

 slope, of the characteristic shoulders, l)enches. and dense talus trains 

 of fragments of the massive Pottsville conglomerates. The entire 

 thickness of the formation seems to have appeared opposite the first 

 knol). at l)ut a short disttuice west of the Fishing Creek Gap. The 

 more northern outcropping of the red shale on the east of the ga"p is 

 (|uite in harmony with the apparently diagonal trend of the fault. 



That the Lower Coal Measures are continuous acrws the gap in the 

 vieinity of the mine drifts is shown not only by the alignment of the 

 coal horiKons and sandstones, but also ])y the character of the fossils. 

 Those colh^cted from the lower coal on the west side are: 



Neuropteris ovata Hoffiu. 

 Neiiropteris Scheuchzeri Hoffm. 

 Calaniites Cistii Brongn. 



PecopterifJ ixjlymorpha lirongii. 



Danjt'ites sp. 



Alethopteris pennsylvanica Lx.? 



It should be recalled that Pecopteris polymoiyha is not known in 

 the lower coals of the Lower Coal Measures, either in the ])itumi- 

 nous basins or in the Northern Anthracite field. 



The species from the upper coal, al)out 170 feet higher, mapped as 

 Lvkens coal No. 4. on the west side of the gap are: 



Peeopterif; miita Brongn (cf. Xcwherryi F. Neuropteris fimljriata Lx. 



& W.). I Linopteris obliqua (Bunb.) Pot. 



Pecopteris oreopteridia(Schloth.)Sternl). i Annularia stellata (Schloth.) Wood. 

 Neuropteris ovata Hoffni. 



Pecopteris unita is an exclusiveh' Coal Measures species, while 

 Neuropterk ovata and Neuropteris jimhrlata are plants having a wide 

 vertical distribution in the Lower Coal ^Measures. 



On tracing the conglomerate, situated about 37 feet above this upper 

 coal, PI. CLXXXVI, Fig. 1, westward from the gap, it was found to 

 pass along the side of the mountain about one-third of the way up 

 the north slope. Roughly measured, it is about 610 feet from this 

 upper conglomerate, over the second coal, or nearly 400 feet from 

 the lower coal, to the upper massive benches of the Pottsville forma- 

 tion, which, for most of the way from this point to Rattling Run, form 

 the narrow "' backbone" or crest of Sharp Mountain. For the latter 

 half of the distance from Fi.shing Creek to the BlacU Spring Gap, to 

 which these u]iper ledges of the Pottsville may easily l)e traced, the 

 second of the adjacent massive conglomerate plates projects vertically 

 from the mountain crest to form an jihnost continuous series of highly 

 pictures<|ue " s-.iw-teeth." which are often 5(» feet in height and nearly 

 as broad. 



It is hardly necessary to cite the unquestionable identify of theso 

 ledges, which are also found at the top of the normal thickness of the 



