16 PP. REPOET OF PROGRESS. FOXTAINE & WHITE. 



15 feet ill thickness, and of these only two ai-e workable 

 over large areas.* 



Flora of The Lower Productwe Measures. 



No special search has been made for plants in this portion 

 of the Coal Strata in West Virginia, and no doubt the list 

 given below might be largely increased by further investi- 

 gations. Two horizons have yielded most of the plants. 

 Tlie lowest is that of the Kittanning Coal Seam near the 

 base of the Series, and the highest is that of the Upper 

 Freeport Coal Seam near the top. 



From the Kittannino- Coal we have : 



Lepidostrobus ornatus. L. & H. 

 Lepidopbyllum. Spec? 



Neuropteris heterophylla. Brt. 



N Clarksoni Lesq. 



Lepidodendron Sternbergii. Brt. 



From the Upper Freeport we have : 



Meuropteris acutifolia. Brt. I Pecopteris arborescens. Schloth. 



OdontoiJteris subcuneata. Bunb. I Asterophyllites rigidus. Brt. 



At both horizons the following pkints occur : 



Pecopteris villosa, Brt. 

 Sphenopbyllum Schlotheimii. Brt. 



Neuropteris flexuosa. Brt. 



N liirsuta. Lesqx. 



N rarinorvis. Bunb. 



But in Western Pennsylvania Mr. I. F. Mansheld has 

 made a large collection of plants for the Second Geological 

 Survey of Pennsylvania from the Darlington bed, which 

 next overlies the Kittanning bed ; and Prof. Lesquereux, 

 the fossil botanist of the Survey, has determined from this 

 material the following species, published in Report of Pro- 

 gress Q, White, 187S, p. 55. 



[* Considering the known thickness of tlie Lower Productive Coal Meas- 

 ures, " barely 250 feet " in the northern counties of West Virginia, — consider- 

 ing that this thickness is wonderfully well preserved in Penns^-lvania for a 

 hundred miles north north-west into the Beaver Valley country, and for more 

 than 150 miles nortla north-east nearlj; to the New York State line, — and con- 

 sidering the absence of reliable data for identification in Middle and Soutliern 

 ■ West Virginia, acknowledged in the text, — one cannot be too cautious in 

 generalizing respecting so extraordinary a thickening of tlie series in that di- 

 rection. My own surveys on Sandy waters in East Kentucky in 18G4, led 

 me to quite the opposite view; for the normal thickness is maintained in that 

 region, if the Hill Sand Rock of Tug Fork be the Mahoning. It will need 

 much "minute examination in the interests of pure science" between the 

 Cheat and the Kanawha before the Mahoning Sandstone can be rightly placed 

 on the latter river; and until that be done it is unsafe to dogmatize about the 

 thickening of the Lower and thinning of the Upper Coal Measures in that 

 direction. — J. P. L.J 



