158 THE CARBONIFEROUS SYSTEM. 



«* 



Coal-group 2 < 



tissue,* vascular bundles of ferns, and. impressions of Sigillaria 

 and Cordaites. It is a compressed vegetable soil or dirt-bed, 

 resting on an argillaceous subsoil with rootlets of Stigmaria. 



ft. in. 

 (Gray and reddish sandstones and gray and red shales 



with ironstone nodules) . . . . . 281 6 

 ' Reddish argillaceous shale. 

 Coal, 1 inch . . . ~| 



Carbonaceous shale, 4 inches > . . .06 



Coal, 1 inch . . ) 



_ Reddish underclay, Stigmaria. 



The coal is coarse, earthy, and shaly. It contains Cordaites, 

 fern stipes, and bast tissue. 



(Reddish shale and gray sandstone, the latter seen 

 in the cliff to thin out and give place to reddish 



shale) 53 9 



( Gray sandstone. 



Coal-group 3 < Coal, 1 inch 1 



( Gray and reddish sandy understone, Stigmaria. 



The coal is coarse and shaly. No fossils were observed, 

 except stumps and rootlets of Stigmaria in the underclay. 



(Reddish gray shale and gray sandstone) . .60 



( Reddish gray shale. 



Coal-group 4 ■< Coal, 2 inches 2 



(_ Gray and reddish argillaceous underclay, Stigmaria. 



The coal is coarse and earthy. No fossils were observed, 

 except Stigmaria rootlets in the underclay. This and the last 

 coal are to be regarded merely as fossil vegetable soils or dirt- 

 beds. 



(Gray sandstone and gray and reddish shale. One 



underclay, and erect Catamites in the lowest bed) 239 6 

 ( Gray argillaceous shale. 



Coal-group 5 •< Coal, 2 inches 2 



(^ Gray argillo-arenaceous underclay, Stigmaria. 



The coal is filled with leaves of Cordaites borassifolia, divid- 

 ing it into thin papery layers. The underclay has many large 

 branching roots of Stigmaria. 



(Gray shale and sandstone) 19 



( Gray arenaceous shale. 



Coal-group 6 ■< Coal, 3 inches •. .03 



{ Gray argillo-arenaceous underclay, Stigmaria. 



This coal is composed of flattened bark of Sigillaria, of which 

 there are many layers in the thickness of the bed. The species 

 are not distinguishable. 



* For explanation as to the nature of these and other structures in the coal, see 

 chapter on " Plants of the Coal Formation." 



