GEOLOGICAL SOCIETY OE DUBLIN. 19 



shale has been sometimes used by the blacksmiths of the neighbourhood 

 in place of better fuel, and has been found to serve their purpose to a 

 certain extent. Immediately underlying this bed we met the sand- 

 stone again, with abundance of plants : in one locality, close to Shalwy 

 shore, we found a bed of yellowish shale at the bottom of the cliff, with 

 Stigmarise scattered through it : these are exposed by the action of the 

 sea, which removes the shale from around them, and leaves them pro- 

 truding from the face of the cliff. ~Not far from this spot, at the oppo- 

 site side of the beach, we found a coarse conglomerate, similar to that 

 which we had met with at Hollybrook, and the mica slate underlying 

 it. From this to Muckrossallagh we observed, in two isolated patches, 

 a skin of this red conglomerate, bleached white, resting on the mica 

 slate. This is further exemplified by the appearance of an outlier of 

 this same conglomerate, forming an island at a place where only mica 

 slate appears on the shore. Before we reached Muckross we saw the 

 Pigeon Caves, which have been excavated by the sea at the junction of 

 the slate and sandstone. Their appearance, owing to the light reflected 

 from their flooring of mica slate, is extremely beautiful. 



From Muckrossallagh to the extreme end of the headland there is 

 shale similar to that at the Binn : however, its strike is different from 

 that of any of the other beds along the coast. 



We were unable to trace the sandstone inland, owing to our having 

 but little time. Prom the appearance of the country it seems probable 

 that the mountain of Crownarad bounds it on the western side. 



I may add, that we observed sandstone similar to that at Dunkineely, 

 and as full of fossils, at Mountcharles, near Donegal. This we did not 

 notice until we were leaving the country, when we walked into a quarry 

 on the hill, which leads up to the town on the west side, while our car 

 was going up the hill. 



Professor Haughton expressed his pleasure at hearing Messrs. 

 Scott and Russell's paper. A controversy had arisen between Irish 

 geologists and some of their friends on the Geological Survey as to the 

 true age of the plant beds in the north and south of Ireland. Mr. 

 Haughton considered that Mr. Scott had clearly established the position 

 of the northern plant beds, as immediately overlying the Old Red Con- 

 glomerate ; and as there could be no doubt of the true carboniferous 

 character of the plants of Donegal, he thought they threw much light 

 on the corresponding beds of the south of Ireland, which, in his opinion, 

 could not be considered as anything but carboniferous. 



Mr. Scott observed that the visitor to Killybegs would have other 

 geology besides that of the carboniferous beds, which would be well 

 worth investigation. There is also in that neighbourhood some of the 

 finest cliff scenery on the coast of Ireland, viz., the cliffs of Slieve 

 League and Glencolumkille, which are at present hardly known, in 

 consequence of the difficulty of communication which has hitherto ex- 

 isted, but which is now to a great extent removed. 



