viii PP. REPORT OF PROGRESS. FONTAINE & AVHITE. 



We were led to confine our examinations and collections 

 to the strata above the Pittsburg coal bed by several induce- 

 ments. One important reason was, that only in this por- 

 tion of the Carboniferous strata could we expect to find any 

 change in the flora pointing to the assumption of a Per- 

 mian facies. Again, the fullest development of the highest 

 beds occurs in West Virginia, and seem to be richer in plant 

 impressions than elsewhere. Another reason was, that the 

 plant impressions found in the Pittsburg and underlying 

 beds, had already received, or would soon receive, ample 

 study in the surveys of the adjoining States. 



Unfortunately we met with many difiiculties in our ex- 

 aminations and collections. The interval between the Pitts- 

 burg coal and the Waynesburg is almost barren of plants. 

 This is due, in part, to their destruction by maceration, and 

 in part, to the fact that much of the interval is occupied by 

 limestones and other rocks deposited under water during 

 an extensive submergence. The paucity of material from 

 this series of strata is all the more to be regretted seeing 

 that the period during which it was deposited seems to be 

 marked by important changes in the flora. 



The Waynesburg coal, as noted elsewhere, is exception- 

 ally rich in plants, and is the highest horizon where they 

 can be obtained with tolerable ease, or in any abundance. 

 This bed, when it is exposed, is generally worked, and thus 

 affords access to undecomposed shales yielding well pre- 

 served plants. But even in this bed, as the plants occur in 

 the shales left by the miners as a roof, special excavations 

 had to be made by us to gain the plants. 



Owing to persistent search, and to visits paid to every 

 point promising good material, we can claim to have made 

 a collection from this bed which is fairly representative of 

 its flora. Some of the localities which have afforded us 

 good material from this bed are as much as 70 miles in air 

 line distance apart, and the points examined are quite 

 numerous. 



Above the Waynesburg bed the exposures are few and 

 poor. Few excavations have been made for railroads 

 and other public works. No coal bed is worked on this 



