44)0 On the Older Rocks ofKillarney and Duhlin. 



Kenmare's cottage. As we cross the strike of the strata from 

 thence towards Mucruss, we find exactly the same purple 

 and greenish compact sandstones which occur in the neigh- 

 bourhood of Cork, Middleton, &c. These, as we ascend in 

 the series, pass into purple slates, and at the Old Weir Bridge 

 the mountain limestone is supported by about 50 feet thick of 

 alternating shales and sandstones, containing the fossils of the 

 limestone, and identical with those of Goat Island, &c. If we 

 follow the limestone to the southern extremity of Turc Lake, 

 we find it again lying conformably upon the same series that 

 I have described as occurring at Glena. I followed these 

 along the course of the stream which runs into Turc Lake 

 from the summit of Manfjerton : and although the want of a 

 good map and the extreme degree of contortion of the beds 

 prevented me from accurately comparing them, I could not 

 mistake the order of superposition, or doubt for a moment the 

 identity of the strata upon the summit of Mangerton. The 

 very upper-beds of the old red sandstone rise from under- 

 neath, but as we proceed to the south these are quickly again 

 covered by newer rocks (Devonian), which pass through all 

 the before-described changes, until in the river Roughty the 

 carboniferous limestone lies on the purple slates without the 

 intervention of any yellow sandstones. 



I am therefore of opinion that the mountains lying between 

 Caranthuel and Kenmare, and between Loch Gutane and 

 the river Roughty, belong to a formation intermediate between 

 the old red sa?idstOfie and carbo7iiferotis limestone, a7id are con- 

 stantly and clearly distingnishahle from both ; and I have little 

 doubt that whatever colour may be adopted to designate these 

 rocks, will be found upon further research to take the place 

 of far the greatest proportion of that which Mr. Griffith has 

 laid down as the oldest slate (Cambrian). 



As to the environs of Dublin, I have already, in the Journal 

 of the Dublin Geological Society, expressed my belief, that 

 the slates and siliceous flags which occur along the coast of 

 Dublin and Louth, correspond with those of the vale of Mid- 

 dleton. I have since satisfied myself of the correctness of this 

 view, and believe that all those tracts which between Dublin 

 and Dundalk, along the course of the Boyne, and in the hills 

 separating the oi(:)unties of Cavan and Meath, have been de- 

 scribed as the older grey wacke by Mr. Griffith, Mr. Weaver, 

 and others, are in reality all conformable and immediately 

 inferior to the mountain limestone, and superior to the old 

 red sandstone. 



The coast of Dublin exhibits a well-developed series of 

 calp, the lower limestone, with its inferior and sandy beds, as 



