342 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 7, 



the Bantry Bay trough of Carboniferous Slate, which is five miles in 

 width. The beds are admirably exposed in the cliffs on both sides 

 of the Bay and in the various hill-sides and brook-chaimels, as far 

 into the country as the eastern base of Shehy Mountain (See Ex- 

 planation of Sheets 192, &c., of 193, of 197, &c., and of 198; also 

 Sections, sheets 19, &c.). Fig. 9 is a section on the north side of 

 this trough m the neighbourhood of Coomhola. 



The beds may be thoroughly examined here, either on the sides 

 of the Coomhola Eiver above Snave Bridge, or on the shores of the 

 Bay from Reenagough Point into Glengariff Harbour. Fossils may 

 be got from the shores about Reenagough and Ardaturrish Points 

 pretty plentifully, but only with much labour and breaking-up of 

 the rocks by strong and heavy hammers. 



The dip here is steady to the south by east at 75° or 80° for a 

 mile and a half at least, with scarcely an interval in which rock is 

 not observable. 



If we take the distance across the edges of the beds at 8000 feet, 

 and allow a dip of 75°, this gives us a thickness of 7760 feet. Of 

 this thickness we may assign 4000 feet to the Old Red Sandstone, 

 taking the uppermost bed of purple slate as its upper boundary. 

 This boundary may be seen at a little cove on the northern part of 

 Ardaturrish townland, where the shore bends to the westward in one 

 direction, and southwards in the other. South of that there are no 

 red rocks, the grits being all greenish-grey, and interstratified with 

 dark- grey or black slates. The beds . of grit are 2 or 3 feet thick, 

 and they occur in groups 200 or 300 feet in thickness, with bands 

 of grey slate of similar thickness between them. They strike steadily 

 from this shore through the Coomhola Glen and along the hill-sides 

 for ten miles to the eastward, and are frequently and largely exposed 

 through the whole distance. They must have an aggregate thick- 

 ness of at least 3000 feet. Above them is a great thickness of black 

 shining slate, probably 2000 or 3000 feet more, in the upper part of 

 which are calcareous bands, becoming in some places crystalline 

 limestone in beds of 2 feet in thickness. 



Mr. Salter and I, with James Flanagan, collected the following 

 fossils when examining the Ardaturrish shore several years ago : — 

 Linear Plants, both in the uppermost red rocks and the lowest 

 grey beds; and a stem of the plant called Knorria (^. Sagenaria) in 

 the grey grits*; Avicula Damnoniensis, Cucullcea trapezium, Cur- 

 tonotus elegans ; species of Lingula, Modiola, Pileopsis, Cythere 

 (Leperditia), besides RTiynchonella pleurodon and other Carboniferous 

 Brachiopoda. In the more purely argillaceous parts of the Carbo- 

 niferous slate, and especially in the calcareous portions of it, Encri- 

 nites and Brachiopods abound, the principal of the latter belonging, 



* In the fine work lately published by the Society des Sciences Naturelles, 

 of Strasburg, entitled ' Le Terrain de Transition des Vosges,' by J. Kcechlin- 

 Schlumberger and Prof. W. Ph. Schimper, the latter learned gentleman has 

 described and figured several fine specimens of these plants, which seem to be 

 precisely identical with those which are so abundant in the upper part of the 

 Old Eed and the lower part of the Carboniferous Slate of Ireland. 



