PIXJEOSTOLOGIGAL REPORT OF GEOLOGICAL SURVEY. 529 



the vast range of distribution of this species, and this peculiarity of 

 a vein of coal preserving, in its shales, a palseontological identity, for 

 more than five hundred miles distance in a direct line. 



Bell's mine, Crittenden county, is extensively worked. This bed has 

 a mean thickness of five feet. The coal has ordinarily one or two 

 inches of cannel at the top of the bed. It is mostly covered by thick 

 sandstone shales, full of leaves of Stigmaria, preserved.in their natu- 

 ral round or cylindrical form, and scarcely flattened. These sandstone 

 shales are not the original roof shales, which are generally wanti ig 

 here, but they have accidentally taken their place, after denudation of 

 the first roof. The same case is observable at Minersville, Pa., in the 

 corresponding bed of anthracite, viz : the second bed above the con- 

 glomerates. The true roof shales are seen in some part of the mines 

 at Bell's, and contain Lingula umbonata in abundance. Near the base 

 of the coal there is a thin bed of rash-coal, containing well preserved 

 specimens of Lepidodendron, Sig'llaria, and Stigmaria. This rash- 

 coal is certainly a peculiar and reliable character, and has been seen at 

 all the places where we had opportunity to examine No. 1 coal — always 

 containing laminated bark of Lepidodedron and Catamites. It is also 

 well marked in the coal fields of Ohio and Pennsylvania, at the same 

 geological level. 



Half a mile southeast of Bell's we were shown the old opening of a 

 vein previously worked, but now abandoned. They called it Cook's 

 vein, and said that it was at a different level from Bell's, viz; about 70 

 feet below. The palseontological remains of the shales prove that this 

 supposition is a mistake. The roof-shales of this coal are the same 

 thick sandstone shales, full of Stigmaria, as at Bell's, and the bottom 

 has the rash-coal, with the Lepidodendron. We did not explore the in- 

 terior of this vein, which is full of water, but the characters were evi- 

 dent enough in the shales heaped at its mouth. 



Between Bell's and Tradewater river, the same vein has been 

 opened and worked, and there also we found the sandstone shales, with 

 round Stigmaria, and the rash coal with Lepidodendron. 



Casey's mine, on the west side of Tradewater river, has its roof 

 shales more developed than Bell's, and shows, in their composition, all 

 the essential characters of the coal on this level. The black slates of 

 the coal contain not only a great abundance of Lingula umbonata, but 



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