538 PROCEEDIXas OF THE WASHINr;T(3N MEETING 



The two papers of Doctor Clarke were discussed b}^ A. C. Lane. E. R. 

 Buckley, G. F. Wright, Bailey Willis, T. C. Chamberlin. J. C. Merriam. 

 and H. M. Ami. 



After announcement by Mr C. W. Hayes that the Photographic Lab- 

 oratory of the Geological Survey was open for inspection of the Fellows, 

 and b}^ the Secretary concerning the order of future papers, the Society 

 adjourned at 12.35 for the noon recess. 



At 2 p. m. the Society was called to order, and Mr G. P. Merrill made 

 announcement of a reception at the United States National Museum on 

 Thursday evening. 



The first paper of the afternoon session was 



PERMIAX ELEMEXTS IX THE DUXKARD FLORA 

 BY DAVID WHITE 



[Ahstract^ 



The Dunkard formation or "series," earUer known as the Upper Barren Meas- 

 ures (xvi), embraces the uppermost Paleozoic sediments in the Appalachian 

 trough. It occupies a large area in southwestern Pennsylvania, eastern Ohio, and 

 northern West Virginia, its greatest thickness, in the last named state, being prob- 

 ably over 1,200 feet. The formation is composed of sandstones, shales, thin lime- 

 stones, and numerous coals. The rocks differ very little from those of the pre- 

 ceding (Monongahela, xv) formatipn, the chief thouo:h not important distinc- 

 tions bein* an increase, on the whole, in the arenaceous elements and a more 

 widespread occurrence of the red or brown color in the shales and finally in the 

 sandstones. 



The organic remains found in the Dunkard are confined to land and fresh water 

 forms, marine conditions having terminated in this portion of the great trough at 

 about the time of the Crinoidal limestone, near the middle of the Conemauirh 

 (xiv). The fossils consist of land plants, insect remains, seldom identifiable fish 

 fragments, rarely present Unionidese, and numerous Entomostrace?e. The two 

 latter groups, though promising much of interest, are unstudied. The determina- 

 tion of the age of the beds rests therefore on the evidence of the floras. 



Fossil plants in large numbers were collected at several localities and described 

 in 1880, by Professors William M. Fontaine and I. C. White in Report of Progress 

 PP of the Second Geological Survey of Pennsylvania. Of the 107 species and varie- 

 ties therein described 72 were new and unknown elsewhere, while of the remaining 

 35 species 22 were listed as common to the Coal Measures of the United States, and 

 28 as coming from the Permian of Europe. From the study of the composition of 

 the flora and the sedimentation in the basin, the authors reached the conclusion 

 that the entire " Upper Barren Measures'' were Permian. This conclusion has 

 been seriously questioned by many geologists and paleontologists on account of the 

 paucity of genera and species characteristic of the Permian of Europe, the large 

 portion of Coal Measures types, and the similarity as well as continuity in the sedi- 

 mentation. To the writer the correlation with the Permian has seemed doubtful 



