WHITE] UPPER LIMIT OF THE POTTS VILLE FORMATION. 827 



It will be observed that of the 5T species enumerated above but 

 9 species, including Mariopteris nervosa^ Pseudopecopteris obtusiloha^ 

 Pseudopecopterls cf. squamosa^ Alethopteris Serlii^ JVenropteris ovata^ 

 ]S[euro2)teris jiinhriata^ SplienophyUum cimeifolitim^ Lepidocystis vesicu- 

 laris^ and Carpolithes transsectus^ are represented even by varieties 

 among- the floras in hand from the Pottsville formation. In fact, it 

 would seem from the examination of the specimens that on\j 5 of 

 the species, viz, Aletlwpteris Serlii^ Neuropteris ovata^ Newropteris 

 jimhriata^ Lejyidocystis vesicidaris^ and Carj)olithe8 transsectiis^ are 

 represented in both series by identical forms, as ma}^ be noted by 

 reference to the floras of beds L, M, and N. Mariopteris nervosa^ 

 Pseudopecoj>teris ohtusiloha^ and Pseudo^yecojyterwci. squamosa are found 

 onl}' in new varieties or doubtful forms in the Pottsville, while, as has 

 previously been remarked, Sphenoj)hyUum cuneifolium is represented 

 bv the broader, more rigid-leaved, and thick-nerved phase character- 

 istic of the Lower Coal Measures. In short, a comparison of the lists 

 shows that less than one-tenth of the ferns are represented b}" identical 

 forms, both in the basal horizon of the Lower Coal Measures and in 

 the upper phytiferous beds of the Pottsville formation. The species 

 common to both formations are largely present in the upper 300 feet 

 of the type section, i. e., the Upper Intermediate division. It must be 

 evident even to one who is not familiar with Paleozoic fossil plants 

 that the fern flora at the base of the Lower Coal Measures in the anthra- 

 cite and other northern coal basins is almost totally different from that 

 of the Upper Lykens division of the Pottsville. 



That the paleontologic characterization of the Buck Mountain coal 

 is similar in the adjoining territory of the Western Middle Anthracite 

 fleld is indicated b}' the following combined list of the floras obtained 

 at the Mahanoy Plane (M); at the Vulcan colliery, 1 mile west of Buck 

 Mountain station (V); at the Buck Mountain mine (B), and from the 

 Big Mine Run colliery, north of Ashland (A), in the latter field. 



Neuropteris ovata Hoffni. (M B A). 

 Neuropteris plicata [Lx.] (B A). 

 Neuropteris vermicularis Lx. (A) . 

 Neuropteris fimbriata Lx. (B) . 



Pseudopecopteris squamosa (Lx.) (V). 

 Pseudopecopteris obtusiloba (Brongn.) 



Lx.(B). 

 Pecopteris pennreformis [Lx.] (M B) . 

 Pecopteris oreopteridia (Schloth.) 



Sternb. (VB). 

 Pecopteris villosa Brongn.? (A) . 

 Alethopteris Serlii (Brongn.) Goepp. 



(AB). 

 Callipteridium cf. Grandini (Brongn.) 



Lx. (B.). 



Neuropteris Scheuchzeri Hoffm. (A M) . 

 Annularia stellata (Schloth.) Wood (B). 

 Sphenophyllum emarginatum Brongn. 



(VB). 

 Lepidodendron aculeatum Sternb. (B) . 

 Lepidophvllum lanceolatum L. & H. ? 



(Bk 



(F) Toward the eastern end of the Southern Anthracite field, in the 

 Sharp Mountain Gap, south of Tamaqua:^ Station 39, PL CLXXX. 



lAtlas Southern Anthracite Field, Pt. I, mine sheet Hi ; Pt. II, mine sheet iv ; Pt. I, cross-section 

 sheet iii, section 12; Pt. I, columnar-section sheet ii, columnar section 49; Summary Final Report, 

 Vol. in, Pt. I, p. 2095. 



