846 FLORAL ZONES OF THE POTTSVILLE FORMATION. 



IMouiitain coal is about 2iU feet; and as the latter is prol)a])ly recog- 

 nizable in this gap, this points toward the level of Lykens coal No. 1. 

 The plants from the Backbone bed, which appears to correspond 

 to the Buck ^Mountain coal at Yellow Springs Gap, constitute a flora 

 agreeing well with that listed from what I believe to be the same 

 horizon at Rausch Gap. The^' are: 



Sphenopteris sp. 

 Pecopteris villoma Broiign.? 

 Neuropteris ovata Hoffiu. 

 NeuropterLs plicata [Lx.]. 



Neuropteris fimbriata Lx. 

 Neuropteris Scheuchzeri Hoffm. 

 Linopteris cf. squarrosa (Ett.). 

 Sphenophyllmn emarginatuni P>rongn. 



Neuropteris capitata Lx. I Rhal)docarpos tenax Lx.'? 



Before passing farther toward the apex of the field, certain sugges- 

 tions, resulting from a comparison of the columnar sections at Yellow 

 Springs and the gaps to the eastward, deserve some attention, although 

 it is not within the province of this paper to attempt the correlation of 

 the coals of the Lower Coal Measures. 



K(>ferring to the section at Kausch Gap (PI. CLXXXVII, Fig. 2), we 

 may ()t)serve that Bill's ])ed. the '* 3-foot" bed, the '•2-foot" bed, and 

 pr()t)ably ''Dan's" bed, have been drifted in the Yellow Springs Gap, in 

 wliich the intervals separating the coals are nearly the same as in Rausch 

 Gap. A hig-her coal opened at Yellow Springs is probably e(|uivalent 

 to that designated the ''Heister" in Rausch Gap, though it may possi- 

 bly be the representative of the coal next below. We may safely 

 conrhide. therefore, on a comparison of these two sections, that the 

 coal in the Pottsville formation from which the Lykens plants enu- 

 merated a))ove were ol)tain(Hl lies approximately 21<» feet below BilFs 

 bed in Rausch Gap, 4i miles to the eastward. 



The section of the Lower Coal Measures at (xold ]Mine Gap exhibits, 

 when compared with that at Rausch Gap, considerable \ariation. If 

 the supposition that the coal which I have designated in the section 

 (PI. CLXXXVl, Fig. 3) the Buck Mountain (Twin) l)ed may be the 

 ec|uivalent of the Bill's bed at Rausch Gap is correct, then the })od 

 known as ""-Ir-foot" bed in the (iold Mine Gap section would appear to 

 l)e (Miuivalent to one or both benchi\sof "Dan's bed" at Rausch (rap; in 

 which case the *' P(Micock" and the coal next above may be par.UleliziHl 

 with coal "Xo. 1 "and the '"Heister" bed, respectively, in the Kausch 

 Gap section, while the two coals next higher at Gold ]Mine may l)e consid 

 ered as representatives of the "(iray" bed and "No. 2" bed at Rausch 

 Gap. The ••No. 4" bed in Rausch Gap lies at the approximate level, 

 stratigraphically, of the "3-foot" bed in Gold Mine Gap. It is obvious 

 that, if these tentative correlations, especially as they relate to the "No. 

 1(0,'' the •• 1 leister." the "Gray," and the ''No. 2" beds at Rausch 

 (iap, are not ei-roneous, the ••Ileister" bed, which, as designated in 

 the published sections, is al»()ut 120 feet above the '•3-f()()t" bed at 

 Gold Mine (iap. can not p()>sibly be the e(|ui\alen( of the bed bearing 

 the >ame name in the Kausch (iap section, less than ;').l miles distant. 



