912 FLORAL ZONES OF THE POTTSVILLE FORMATTOX, 



formation here jiceepted is oorroct. it is possible that thoro is a slio-ht 

 overlap of Pottsville time on that of the Mauch Chunk formation, in 

 which case its designation as Coal Measures would he lithologic and 

 economic only, rather than strictly accurate from the chronologic stand- 

 point. 



The flora of the Vespertine (Pocono X), which has received atten- 

 tion from Lesquereux', Meek' and Fontaine,^ like that of the cor- 

 responding Horton series of Nova Scotia, studied bv Sir William Daw- 

 son, consists of an almost exclusively Triphyllopterid or Aneimites 

 flora, with several laciniate-lobed Sphenoptrrldx, and great numbers 

 of Lepidodendron of the corrufiatum, type. The flora of the Mauch 

 Chunk formation is as yet l)ut little known; but such material as has 

 come to hand from the upper portion of the formation shows a marked 

 affinity with the Pottsville flora. The Chester limestone of Illinois 

 is said to have furnished some fossils which are closely related to those 

 of the basal Pottsville beds. I may add that the Anet notes from the 

 topmost ])ed (bed A, PL CLXXXII) of the red shale at the Westwood 

 and Pottsville gs^.ps appears to be more closeh' bound to the Lower 

 Carboniferous types than to the ordinary plant life of the Pottsville 

 formation, and should, therefore, perhaps be excluded, together with 

 the accompanj^ing Sphenopteris umhratilis^ from the flora under con- 

 sideration. 



The plants of the Lower Lykens division, as a whole, appear to stand 

 in the closest relation to the flora of the Ostrau-Waldenburg beds 

 described by Stur* and generally regarded as Lower Carboniferous 

 ("Culm"), though many geologists and paleontologists are strongly 

 disposed to refer the terranes to the Millstone grit. The intimacy of 

 the relationship, and the probalfle contemporaneity of our flora with the 

 I'pper Culm flora will ])e more fully indicated when the Pottsville flora 

 is treated more at length, in the monographic report. 



The flora of the Upper Lykens division seems to be directly related 

 to that of the Millstone grit (rf Canada and portions of the Carbon- 

 iferous basins of the Old AVorld, though the data for comparison are 

 hardly satisfactorily complete. Th(> upper horizons of this division 

 have also much in conunt>u with {\w flora of the Lower Coal 

 Measures of Great Britain. The latter, it luay ])e noted, are, for the 

 most part, paleobotanically oldt»r than tiie foiMiiation known by the 

 same name in the Northern States of this country. 



The Upper Intermediate division would seem, from the identities 

 and distribution of its plant sp(HMes, to be as late as the Lower Coal 

 Measures of Great Britain, or the lower zones of the Westphalian in 

 continental Europe. 



Mk-ol. Pennsylvania. 1h.tS, Vol. II, Pt. II. 

 -Bull. Philos. Soc. Wa.>;liington, 1K79, Appendix. 

 "Am. Jour. Sci., 3(1 surits. Vol. XIII, 1S77, pp. 3.\ ll.=>. 

 < Abh. A. k.-k. geol. Reieh.sanst., Vol. VII, 1.S77. Pt. II. 



