WHITE] PLANTS OF THE POTTSVILLE IN SOUTHERN FIELD. 865 



than tho Fottsvilli'. In certain instances cong-lomeratic .sandstones 

 and conglomerates compose about one-third or more of the entire 

 section. As might be expected, this feature, which is well illus- 

 trated in the sections located in the Tremont region' and in the 

 Panther Creek Basin, is not less striking than the astonishing varia- 

 bility in the thickness of the intervals separating the coals of the 

 Productive Coal Measures in the same regions. In this connection it 

 is both interesting' and instructive to make a comparison of the 

 columnar sections published in columnar-section sheets x of Pt. IV, 

 vi of Pt. 11, and iii of Pt. I. of the Atlas of the Southern Anthracite 

 Field. 



IS^OTES OX OR DESCRIPTIOXS OF SOME OF THE 3IORE 

 CHARACTERISTIC SPECIES OF FOSSIE PLANTS OF THE 

 POTTSVIEEE FORMATION IN THE SOUTHERN ANTHRA- 

 CITE FIEED. 



It was my original purpose to have the description of the strati- 

 graphy of the Pottsville formation in the Southern Anthracite tield 

 accompanied by full descriptions and illustrations of the fossil plants, 

 which, with the exception of Sp/'/vr/ji.s, rare crustacean fragments, 

 or still rarer cockroach wings, appear to constitute the sole organic 

 remains yet brought to light. When, however, it was found not only 

 that the manuscript and plates were too voluminous for the present 

 form of publication, but also that the subsequent preparation of a 

 complete report covering- the fossil plants of the formation in other 

 portions of the Appalachian province would include the repul)lica- 

 tion of many of the descriptions of the fossils from the Southern 

 Anthracite field, it was determined to confine this report to the 

 description, limitation, and definition of the Pottsville formation as 

 found in the type section and region, and such economic or general 

 g-eologic results as had been reached in the course of the paleontologic 

 and stratigraphic studies in the field, as well as such general or 

 broad correlations as might be proper in a preliminary paleontologic 

 publication. 



The following pages are devoted to descriptions of some of the 

 more important stratigraphic species of the several zones of the Potts- 

 ville formation or to notes, either relating- to species already known 

 elsewhere or concerning forms closely allied to well-known types. 

 Following is a list of the entire flora. 



1 See polumnar-section sheet x. Atlas Southern Aiithnicitc Field, I't. IV B; and columnar-section 

 sheets i and ii, respectively, of Pt. I of the Atlas. 



20 GEOL. 11' 2 55 



