174? PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



6. There are twenty- three seams, occurring in succession, most of which 

 are not distinguished by any term indicating quality ; in two instances, 

 one a three-feet seam, they are said to be bituminous, and several seams are 

 said to be binding, which means the same as caking, a quality which only 

 richly-bituminous coals possess ; the rest are merely called " Coal.'* These 

 twenty-three seams with their interstratified sandstones and shales occupy 

 1840 feet. 



7. Then succeed thirteen seams, in a space of 1000 feet, and nine of 

 these are described as " not bituminous," 



8. The thirty-seventh seam, in descending order, is said to be anthracitic, 

 and fourteen seams below it are so designated : then come four seams 

 merely called ''Coal," and all very thin. Beneath the lowest of these, 

 and separated by sixty feet of arenaceous shales and sandstones, comes a 

 bed of coal, four feet six inches thick, called Anthracite, with five feet of 

 underclay ; beneath this are seven seams called Anthracite, and three more 

 are intercalated called anthracitic. 



9. Between the thirty-seventh seam, called Anthracitic, and the lowest 

 of all, which is called Anthracite, there are twenty-two seams intercalated, 

 without having any distinctive term affixed to them, most of them very 

 thin ; but about midway, three occur near together, without intermediate 

 sandstones and shales, but separated by clay containing Stigmarise, in the 

 following manner : — 



ft. in. 



Coal 1 



Underclay 4 



Coal 4 



Underclay 8 



Coal 1 4 



Underclay 8 



10. The seams of coal, whether termed merely " Coal," or bituminous, 

 or anthracitic, or anthracite, have, with very few exceptions, underclays, 

 and these, generally, but not uniformly, contain Stigmarise. The two lowest 

 beds of anthracite have underclays of five feet each, the third from the 

 bottom has seven feet of underclay, each with Stigmarise. The underclay 

 is of variable thickness ; in no part more than fourteen feet, and except in a 

 few instances, is always said to contain the Stigmaria ficoides. 



11. There appears to be no relation between the thickness of the under- 

 clay with Stigmarise, and that of the coal resting upon it. The thickest 

 seam of coal, which is nine feet, rests on three feet of underclay, and there 

 are instances of a seam of coal only an inch thick, with five feet of under- 

 clay stated to he filled with Stigmaria. 



12. A bed of clay, eight feet thick, with Stigmarise, has no coal upon it, 

 but a foot of carbonaceous shale ; and above that forty feet of arenaceous 

 shale, then four feet of clay with Stigmarise, covered by three inches of 

 coal, and that overlaid by twenty-five feet of argillaceous shale and sand- 

 stone. 



13. In no case is any difference stated in the mineral character of the 

 sandstones or shales either over or under the Anthracite seams, or of any 

 other coal-seam. 



The example from Nova Scotia is a vertical section on the same 

 plan as that in South Wales; and the coal-measures there also rest 

 upon limestone, containing organic remains, " among which there is, 

 in some abundance, a bivalve shell which Mr. Logan recognised as 

 identical with Producta Lyelli of Windsor in Nova Scotia." This 



