PALEONTOLOGIC NOTES FLORA 171 



but at that time believed by all to be the Waynesburg; 1-4 are peculiar 

 to the Doddridge horizon; 9 are confined to the Washington coal or 

 higher horizons, while 11 have a great vertical range, some surviving- 

 from the Doddridge shale to 600 or 800 feet above the Waynesburg 

 coal bed. 



The final chapter of the work is an elaborate comparison of this flora 

 with European forms, including also a comparison of the physical 

 changes closing the Carboniferous of this area with those closing the' 

 Carboniferous and Permian of Europe. The conclusion reached by the 

 authors is that the Upper Barrens of the Appalachian field (Washing- 

 ton and Greene formations) are of Permian age, and this is based on 

 evidence from identical or allied species, the decadence of Coal Measures 

 forms, the introduction of types characteristic of later formations as 

 well as on that from physical contrasts between the Upper Barrens and 

 the preceding formations. They find that 28 species are common to 

 the Upper Barrens and the Permian of Europe, of which 12 have been 

 found in the United States Coal Measures, while 2 are exclusively Per- 

 mian and 4 others are closely allied to European Permian forms. 



The importance of this communication was recognized at once, but 

 the conclusions were not accepted as final, chiefly because of the paucity 

 of known material from the x\llegheny, Conemaugh, and Monongahela 

 formations which might be used for comparison. No further investi- 

 gation of the problem was made for almost 23 years, until Mr David 

 White, after study of extensive collections from the earlier formations, 

 undertook preliminary revision of the horizons discovered and discussed 

 by Professors Fontaine and I. C. White. The results of this revision 

 were published in 1903.* The collections, made at the typical as well 

 as at other localities and horizons, led Mr White to place the forms in 

 five categories: 



a, those characteristic of the Eothliegende or higher formations of 

 the Old World ; i, those closely allied to Permian types ; c, those whose 

 habit or facies suggests a late date; d, those of Mesozoic aspect; e, Coal 

 Measures type. 



In the first category Mr White places 3 species of Oallipteris, one each 

 of Goniopteris, Pecopteris, Alethopteris, Odontopteris, Gaulopteris, 

 Equisetites, and Sigillaria, with 2 species of Sphenophyllum; in all, 1^- 

 species. In the second are also 12, but the author states that the num- 

 ber might be extended according to the personal equation of the observer 

 or to the amou^nt of material available for comparison, while, at best, 



* D. White : Permian elements in ttie Dunkard flora. Bull. Geol. Soc. Am., vol. 14, pp. 

 538 et seq. 



