311 Lepi. 



Lepidodendron. Tree-like fern stems, often of great size, 

 100 feet or more in length, bearing leaves on the young branches 

 or shoots. At Ashland, in the western middle anthracite field, 

 there was formerly a famous exposure of sandstone, not far 

 above the Conglomerate, where scores of these trees of great 

 length could be seen lying diagonally across each other as if a 

 forest had been blown down. The roof of the old Olarkson 

 coal bed at Carbondale in Lackawanna Co., Pa. is almost en- 

 tirely covered with impressions of trunks, some 70 feet long 

 and 2 feet wide, which do not taper at all at the upper end and 

 therefore must have been much longer. A forest of them is 

 preserved in sandstone at the Falls of the Little Beaver river 

 in Western Pennsylvania. A few logs evidently drifted, were 

 seen by Claypole in the Pocono sandstone iV^. X, in Perry Co. 

 Pa. Lesquereux (in Geol. Pa., 1858, page 873) remarks the 

 astonishing perfection of the fossil scars, many specimens in 

 the magnificent old collection of W. Clarkson in Carbondale, 

 and of Mr. Moore in Greensburg, being as distinct as though 

 they had been carved in the stone by a good engraver. 



These tree fern forests, with their stems {Lepidodendron) 

 leaves {Lepidophyllum^) and their cones or fruit {Lepidostro- 

 bus) began to exist at the opening of the Upper Devonian age ; 

 abounded in the Lower or Sub-carboniferous ages ; and died 

 out in the Barren measure times. Commencing below and 

 going up in the formations, we have them mixed with early 

 Calamites, or reeds, in the top Chemung- Catshill shales, as in 

 Smith's valley and Clear ridge, Huntingdon Co.. Pa. (T3, 102). 

 — Then, in the abortive coal age of the Pocono^ as in Claypole's 

 stem specimen (221-1) from Mt. Patrick, Buffalo, Perry Co., 

 (and another large cast, not numbered in the collection,) show- 

 ing drifted logs (only a few found, but doubtless multitudes in 

 all ;) as in the upper layers of the 730' beneath the Shoups run 

 red shale, Huntingdon Co., and the PR. tunnel through Side- 

 ling hill (T3, 88) ; and in the A, B, C, D, and E, divisions of 

 Randall's section at Warren, Pa. — Then, in the Pocono sand- 

 stone under the Conglomerate, XII, in the Venango oil region 

 hill tops, around Pleasantville, etc., from which Carll collected 

 his specimens (0) 2790, 2798, 2804, 2928, 2938, 3072.— Then, in 

 the Conglomerate itself, as in the roof-shale of the Sharon coal 

 in Mercer Co. (Q3, 53, 123, 126, 160), and in the lowest coal 



