524 Scientific Proceedings, Royal Dublin Society. 



are not of much account, except that in some places they produce 

 good flags. Here it may again be mentioned that, in the lime- 

 stones of the Calp of the Co. Limerick, there are many Lower 

 Carboniferous Sandstone and Shale fossils. 



In Leinster and South Connaught the Carboniferous rocks are 

 very similarly circumstanced to those of North Munster, but in 

 North-east Connaught and Ulster there are marked changes. In 

 the south portion of Ulster and adjoining part of Connaught 

 there comes in as a middle group in the limestone, or as indepen- 

 dent groups or beds on different horizons, very pure arenaceous 

 rock; they, the Calp Sandstones, being quite distinct from the 

 Yellow Sandstones below and the Coal-measures above. In these 

 Calp sandstones, the " Fermanagh sandstones," and the Calp of the 

 Ulster type, are procured the stones now of most note in the 

 market. As a rule, the sandstones in the Coal-measures are con- 

 sidered too hard, although in Leinster some of them are really 

 good stones ; while the Lower Carboniferous stones are often 

 ignored. This, however, may be due to prejudice or some other 

 cause, as near Thurles and Dunclrum, Co. Tipperary, there are- 

 stones said by the builders who have worked both to be better than 

 any of the "Dungannon stones" {Calp). 



At the present time the geology of South Tyrone, the extreme 

 north part of Monaghan, and the adjoining portions of Fer- 

 managh seems to be mixed up. In this area, in Slievebeagh, Carn- 

 more, and in the country to the eastward, there are sandstones and 

 shales that Griffith mapped as Calp, because apparently they were 

 identical with the Calp near Dungannon, in Co. Tyrone. John 

 Kelly, however, stated that they belonged to the Coal-measures,. 

 and called the highest group " Millstone Grits ; " and in the recently 

 published maps of the Geological Survey, John Kelly's classifica- 

 tion has been followed, and they have been mapped as Lower 

 Coal-measures, the lower portion being called by Phillips' local 

 English name, Yoredale beds ; it being here divided into Yoredale 

 sandstone and shales, while the upper sandstones are called Mill- 

 stone Grits. 



[It seems very questionable if it is advisable to introduce English local terms into- 

 Irish geology, more especially when they are inapplicable. Anyone who has compared 

 the Irish Coal-measures with those of England should be aware that the first can only 

 he compared with the "Culm-measures" of Devonshire, while there is no similitude 



