1877.] 4:1 i [Lesquereux. 



to the identification of the coal beds was confirmed by the opinion of 

 the minerS; who, wlien questioned on the su])ject, generally asserted 

 that it was for them an easy matter to tell one coal from another by 

 comparing tlie roof shales, and their remains of plants. My first attempt to 

 a determination of t,his kind, in connection with the first Geological Survey 

 of Pennsylvania, was, as observed by Professor Lesley, a marked failure. 

 For I considered the Salem vein of Port Carbon as the equivalent of the 

 Mammoth, while these represent the two extremes of the Anthracite meas- 

 sure«, one at the base, the other in the upper part. But paleontology is not 

 accountable for a personal blunder, which, moreover, was forced upon me 

 by peculiar circumstances which, if they do not make it excusable, 

 at least explain it. I had found, back of the hill facing Port Carbon, 

 just after passing tlie cut of the railroad entering Mill creek, large heaps of 

 shale extreme!}^ rich in fossils, and had there made a prolonged search for 

 the study of a well determined local flora, when I was informed by a miner 

 that I should find opposite, and at the foot of Sharp Mountain, the same kind 

 of shale with abundant specimens of the same plants. There, indeed, 

 I found Peciipteris arborescens, an essentially characteristic species of the 

 upper coal, with Neuropteris Loschii, and other species seen at the first lo- 

 cality ; but with them were remains of Lepidodendron, of species of Sig 

 illaria and of Alepthopteris, which I had formerly recognized above St. 

 Clair, in couuec.ion with the Mammoth vein. This seemed so extraordi- 

 nary that I visited the same places many times on the supposition that I 

 had been mistaken by false appearances in the characters of the plants ; but 

 the same evidence was always there ; and I came to the conclu- 

 sion that from all appearances, that coal of Port Carbon was the equiva- 

 lent of the Mammoth, though differently placed by Professor R>>gers. For 

 all the coal beds along the valley of Mill creek are turned up vertically, and 

 therefore, their relative position was at that time unascertained. It was only 

 after years, that in my raral}les around Pottsville, on revisiting again the 

 heap of shales of Sharp Mountain, I was informed by the Superintendent of 

 a coal mine whom T met in the vicinity, that these debris were from a tunnel 

 pierced through a number of small veins including the upper ones, to reach 

 the bottom vein, the Mammoth, which was found there too thin to be 

 worked and had been abandoned. Therefore the remains of plants of a 

 number of coal beds of different horizons were there mixed together. I 

 do not say this in order to support an opinion which, in regard, at least, 

 to the application of vegetable paleontology to the identification of coal 

 strata, has been, by long experience, if not altered, at least reduced in the 

 main. For I know well, now, how rarely remains of fossil plants are 

 found in the same degree of profusion in connection with coal beds of the 

 same horizon ; how rarely, when these remains are found, they represent 

 the same species, or, at least, have them in the same proportional distribu- 

 tion ; and how careful and protracted the study of the flora of the same coal 

 has to be before it is possible to know the peculiar species which may be- 

 long exclusively to it, or be considered as the leading ones. For this 



