792 FLORAL ZONES OF THE POTTSYILLE FORMATION. 



lowor portion of the Pottsville formation. Sj>/u'?)oj)te?'i.s jx/fe)7tissima 

 appear.s to he present at this level, though more common in and charac- 

 teristic of the roof of coal No. 4. Calamostac/ti/s- cf . lanceolata^ collected 

 from the East Brookside rock dump, ma}' ])c assumed to have come 

 from No, 4, its occurrence in other regions being as high as the flora 

 of No. 4, or even hig-her. The same is true of Lepidodendron aldbmnense. 

 Le2)idoj)hi/Uiun hniceolatinn var. virg'nviaimm and Lej^f'dojyJiylhnn 

 qui)i)il))iontanu7n are essentially characteristic of the lower Pottsville in 

 all regions, but the former is usually predominant in beds lower than 

 those in which the latter is common. 



From an examination of the table, as Avell as from the inspection of 

 the collections, we may conclude that the almost invariable appearance 

 of 2[nr'wj>terisi eremopteroides or the lax form, var. incequah's, of JTeu- 

 7'oj)tens Pocahontas^ as well as the occasional presence of a number of 

 the ferns slightly more characteristic of No. 4, serves to distinguish the 

 stage of coal No. 5 from the basal portion of the Pottsville formation, 

 while the species first mentioned, together Avith the always abundant 

 Neuroi^tei'is Pocahontas \?a\ pentias^ Neiiropteris Pocahontas ^ q.i\^ Lejri- 

 dophyJlum lanceolatum var. virginiannm^ likewise assist in discriminat- 

 ing between the floras of coals No. 5 and No, 4. In the latter differ- 

 entiation the absence of those plants which are characteristic of the 

 roof shales of No. 4 is perhaps an (equally valuable criterion, though 

 negatiA'e in its nature. 



l'AL?:()NTOLO(Ut' FEATURES OF THE KOOF SHALES OF COAL XO. 4. 



The flora of the roof shales of Lykens coal No. 4 is perhaps the most 

 readily recognizable among- those attending the series of the Lykens 

 coals. While it contains a large percentage of species that are also 

 found in the roof of No. 5, as ma}' be noted by reference to the ta))le, 

 and while its facies is distinctly hnct-i' Pottsville as compared with 

 floras of coals 2 or 3, it almost invarial)ly contains several species 

 Avhich arc not only restricted to nearly this level in the Southern 

 Anthracite held, l)ut which are also observed, similarly associated, and 

 restricted as to vertical range, in other regions. These are Aneimites 

 2Jottf<%u7h'nsis, Jfarioj/te/'is jMfftsviNea, Aleth( pterin protdqiiUina^ Neu- 

 mptti'ls Snilthsii^ YoIl'iiKintiia ci'dMsa, and Sphmoj/hi/Z/i/ni tenue. 

 Additional species, hitherto found only at tiiis level in the Southern 

 Anthracite fleld, are Sjylnnopterls lioralhicolniana^ S. Lutlu-rhina^ 

 PJiiijtdoniipos sj/t'C/osus^ and a form of Sporangites. Of the species 

 which are found at other horizons, Sphenopteins pateniissima^ the 

 small form of .V. a.^phnnoldes^ AJoiopterisgeorglana^ Ltpidodoidron (da- 

 Jxniiensi'^ and Trujonocarpum Ildtmcv. are more especially common in 

 this stage, where they are generally associated with the species flrst 

 enumerated. In fact, Aneiiintes j'ottsvillensis^ Mar'wpterls pottsvillea^ 



