162 THE CARBONIFEROUS SYSTEM. 



(Sandstone and red and gray shale, with one Stigma- ft. in. 

 rian soil) ... ..... 93 3 



( Red shale. 



Coal- group 21 ■< Coal and carbonaceous shale, 2 inches . . .02 



(_Gray argillaceous underclay, Stiymaria. 



In the bed above the roof- shale are erect Calamites. The 

 coal is an uneven or irregular bed, and consists of flattened 

 Sigillaria}, Cyperites, Cordaites, and ferns. 



(Gray and reddish sandstones and shales, with drift- 

 trunks of Dadoxylon materiarium, Sigillaria, and 

 Calamites) ....... 334 



( Gray and red shale, nodules of ironstone. 



Coal-group 22 < Coal and carbonaceous shale, 2 inches . . .02 



(_ Gray argillo-arenaceous underclay, Stiymaria. 



This coal consists of flattened bark of Sigillaria with Cor- 

 daites and vascular bundles of ferns. It contains also remains 

 of fishes. Among these was found a tooth of Ctenoptychius. 

 The underclay includes stumps of Stigmaria, as well as rootlets. 



(Gray sandstone and shale, with one Stigmarian soil 



supporting erect stumps of Sigillaria) . . . 68 



Total thickness of Division 3, according to Logan's measurements 2159 8 



Division 4. 



This division of the section extends from M'Cairn's Cove to the end 

 of the high cliff beyond " Coal-mine Point." It corresponds to the 

 lower part of the Middle Coal Formation, and probably to the Lower 

 Coal Formation of some American authors. Its thickness, according 

 to the measurements of Sir William E. Logan, is 2539 feet. It is 

 remarkable for the prevalence of gray sandstones and gray and dark- 

 coloured shales. It constitutes the part of the section re-examined 

 by Sir C. Lyell and myself in 1852 ; and in the memoir which I 

 subsequently published, it is divided into 27 groups or Subdivisions. 

 For facility of reference, these groups are indicated by the Roman 

 numerals in the following pages, beginning with the highest group, 



XXVII. 



XXVII. 



f Bituminous limestone and calcareo-bituminous shale, ft. in. 

 n t 1 4 feet. 

 Coal-group 1 i Coal, 1 foot /. .50 



[ Gray argillo-arenaceous underclay, Stigmaria. 



The roof has Naiadites carbonarius and N. elongatus, Spirorbis 

 carbonarius, scales of Rhizodus, and obscure vegetable frag- 

 ments. The coal contains flattened Sigillaria^, Cordaites, 

 Alethopteris lonchitica, Cyperites, Calamites Nova-scotica y and 

 many vascular bundles of ferns. 



