152 Dr. Berger o« /^<r Geological Features 



in that direction. Were the sea to retire a few fathoms and 

 disclose the foundations of Rathlin, we should very probably 

 discover the trap which constitutes the present surface of that island, 

 resting on the old sandstone ; and that rock in its turn reposing 

 upon syenite. 



III. FLOETZ ROCKS. 



A. Limestone underlying the Coal formation. 



B. Coal formations. 



C. Sandstone formations, 



D. Lias. 



E. Green Sandstone or Mulattoe. 



F. Chalk. 



A. Limestone* underlying or associated with the Coal Formation, 



At the entrance of Cookstown on the road from Coagh, there 

 are quarries of a shell limestone formation supposed to extend 

 itself to the south as far as to Steward's town, and nearly for one 

 mile in the other directions: it is disposed in strata alternately 



* The limestone here described appears to constitute a portion of that great limestone 

 formation which maybe traced through the counties of Kilkenny, Kildare, Dublin, the 

 Meaths, Roscommon, the south-east of Mayo, Sligo and Fermanagh. The great coal 

 districts of Kilkenny in the south, and of Lough Allen in the north, repose upon it; as 

 aJso do those of Dungannon and Coal Island described in the next article. 



The points described in the text are principally situated on the north-west of the coal 

 formations last mentioned, and near the line separating the sandstone associated with the 

 coal, from the primitive mountains coonected with the great chain of Londonderry. 



