1865.] 



DAWSON COAL-FORMATION. 



113 



Coal-group 6 



XXIII. 



f Carbonaceous shale, passing downward into bitu- ft. in. 

 minous limestone, 1 foot 10 inches. 

 Co«^4iuches 2 2 

 Argillo-arenaceous underclay, Stigmaria. 



The roof contains Naiadites carbonarius, Cythere, /Spi- 

 rorhiSf fish-scales, and coprolites. The coal is hard and 

 laminated, and has on its surfaces leaves of Cordaites and 

 vascular bundles of ferns. It is remarkable for containing 

 scattered remains of a number of species of fishes, belonging 

 to the genera CtenoptychiuSj Diplodus, Pcdoeoniscus, and 

 JRliizodus. The underclay has rootlets of Stigmaria, and 

 the bed below this has large roots of the same. 



(Grey sandstone and shale, the latter with nodules of 



ironstone. Erect trees at one level) 30 



(OcvQj sandstone. 



ICoal 10 inches. 

 Carbonaceous shale 2 inches 

 Coal 10 inches. 

 Carbonaceous shale 2 inches. 



CoaZ and coaly shale 2 feet 6 inches 4 6 



^ Grey argillo-arenaceous underclay, Stigmaria. 



This is the bed worked at the Joggins as the **Main 

 Seam ;" and I believe that it improves somewhat in mining 

 it inward from the shore. The roof has afforded Sigillaria 

 catenoides and other species, Alethopteris lonchitica, CoV'- 

 daites horassifoUa, Lepidodendron elegans, Trigonocarpa, 

 Naiadites, Spirorhis, Cythere, fragments of insects (?). The 

 mineral charcoal contains bast tissue, scalariform, epi- 

 dermal, and cellular tissues. In the compact part of the 

 coal there is dense cellular and epidermal tissue. The roof 

 is especially rich in Cordaites, sometimes with iSpirorhis 

 adherent. 



(Grey sandstone and shale, with many ironstone 

 nodules in the shale, and erect Sigillaria and un- 

 derclays at five levels. One of the latter has large 

 stumps of Stigmaria and a thin coaly layer 



resting on it) 68 



( Grey shale with nodules of ironstone. 

 Coal 2 inches. 

 Grey shale 4 inches. 

 Coal 3 inches. 



Carbonaceous shale 1 foot 3 inches. 

 Coal 1 inch. 

 Argillaceous shale, ironstone nodules, 4 feet. 



Coal 1 foot 7 1 



Grey argillo-arenaceous underclay, ironstone no- 

 dules, and Stigmaria. 



The roofs of the first and second beds in this group are 

 among the richest in fossils in the Joggins section. They 

 have afforded Pecopteris lonchitica, Cydopteris, Cyperites, 

 Cordaites horassifolia, Cardiocarpum Jluitans, Sigillaria 

 elegans f Lepidophloios Acadianus, Lepidodendron undidatum, 



Coal-group 8 ... " 



