172 THE CARBONIFEROUS SYSTEM. 



alternating with bright coal ; it has obscure impressions of 

 plants and bast tissue in the mineral charcoal. 



x. 



(Gray shale and sandstone. One underclay, and ft- in. 



erect Catamites and Sigillaria at two levels) . 19 



Gray sandstone. 



Coal and coaly shale, 1 foot. 



n , n , Underclay, Stigmaria, 1 foot. 



Coal-group 31 j q. ^ 6 f nches / 



Coal, 2 inches . . . . . . .28 



Argillaceous underclay, Stigmaria. 



The roof contains Sigillaria;, and the coal has flattened 

 impressions of the same. This coal is remarkable as having a 

 roof of sandstone. Its underclay is also peculiar. It is about 

 9 feet in thickness, and contains Stigmaria and nodules of iron- 

 stone throughout. It rests on a bituminous limestone contain- 

 ing Naiadites and scales of fishes, and also large roots of Stig- 

 maria evidently in situ. This bed gives more colour to the 

 idea of Stigmaria having grown under water than any other 

 bed at the Joggins. I believe, however, that it merely implies 

 the drying-up of a pond or creek into a swamp, subsequently 

 inundated at intervals with muddy water. 



(Underclay and bituminous limestone, succeeded by 



sandstone and shale) . . . . . . 27 8 



( Gray shale. 



Coal-group 32 -< Coal, and coaly shale, 2 feet 4 inches . . .24 



(^ Argillo-arenaceous underclay, Stigmaria. 



This is a series of thin coaly bands alternating with shales. 



The roof contains trunks of Sigillaria, Cordaites, Alethopteris, 



and Cyperites. The coal has numerous flattened trunks of 



Sigillaria. 



Gray and reddish sandstone and shale. Five under- 

 clays, one with a film of coal and erect Sigillaria} 



at two levels) 149 



( Coaly shale. 



Coal-group 33 •< Coal, 1 inch 1 



(^ Argillaceous underclay, Stigmaria. 



The roof has flattened trunks and vegetable fragments. The 

 coal is a mere soil, with remains of Sigillaria and Cordaites, and 

 vascular bundles of ferns. 



(Red and gray sandstone and shale) . . . 45 



( Gray shale. 

 Coal-group 33a....-< Coal and coaly and gray shale (underclay). 

 (^ Argillaceous underclay, Stigmaria. 



These layers, though not of sufficient importance to be 

 measured as coal-bands, are most interesting as furnishing 



