438 PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. [JuilG 18, 



In the remarks accompanying the * First Sketch of a New Geolo- 

 gical Map of Scotland,' published in 1861, Sir E. I. Murchison and 

 Mr. Geikie say, at p. 13, — 



'* Another chief feature of the present map, as distinguished from 

 all other maps of the country, consists in the subdivision of the Car- 

 boniferous formation. 



*' This group of Eocks consists in Scotland of the following mem- 

 bers : — 



Scotch Series. English Equivalents. 



Upper or Flat Coals Coal-measures. 



Moor-rock, or Eoslyn Sandstones . . . Millstone-grit and Upper Limestone-shales. 



cX„^eS\fine } Carboniferous linestone. 



Lower Carboniferous Lower Limestone-shales. 



*' The Upper Coals represent, wholly or in part, the true English 

 Coal-measures, which lie above the Millstone-grit. They occur, in 

 Scotland, in four basins, — one in Mid-Lothian, a second in Fife, the 

 third and largest along the Clyde, south-east of Glasgow, while the 

 fourth occupies a small area in Ayrshire. The position of the Mill- 

 stone-grit has not yet been satisfactorily traced, and is therefore 

 not shown on the present map. The Lower Coals are understratified 

 in their higher and lower portions with seams of marine limestone, 

 the fossils of which identify the series as the equivalent, partly ter- 

 restrial, partly marine, of the Carboniferous Limestone of England." 



The above authors are quoted to show what information has lately 

 been published on the divisions of the Scottish coal-fields ; but, so 

 far as my knowledge extends, no evidence, either in England or 

 Scotland, has come before me which decidedly establishes the terres- 

 trial character of a single fossil, either vegetable or animal. With 

 Mr. Moore, also, I consider that the Upper Coals occupy a somewhat 

 larger area in Ayrshire than the authors of the map have afforded 

 them. But, on the other hand, Mr. Moore appears to have taken in 

 all the Permian sandstones, as belonging to this division ; so that 

 the correct area will probably lie between the two views. It is 

 quite clear that both the divisions of the authors are convenient and 

 natural, and will greatly assist in investigating the country. 



After an examination of the English and Scotch coal-fields, my 

 opinion is that the Muir-stone Eock occupies nearly the position of 

 the Millstone-grit; but the lower portion of the Middle Coal- 

 measures of Lancashire and Yorkshire is represented by the Ayr- 

 shire beds at Common, worked by Mr. Lancaster, of the Portland 

 Iron Company. Beds of Anthracosia, so far as my experience goes, 

 are not of great value, when taken alone, in identifying particular 

 strata in the Coal-measures ; but if one fossil has more value than 

 another, it is the large Anthracosia {A. rohusta) found about 65 

 yards above the ^* Arley Mine " of Wigan. Now in the black- 



the Eoyal Scottish Society of Arts, by Ealph Moore, Mining Engineer, Grlasgow, 

 with coloured plans and sections of the coal-fields in the Counties of Ayr, Ren- 

 frew, Dumbarton, Stirling, Linlithgow, Edinburgh, and East Lothian." Glasgow, 

 1861, p. 9. 



