On the Old Red Sandstone of the North of Ireland. 133 



9. " On the Old Red Sandstone of the North of Ireland." By 

 F. Nolan, Esq., M.R.I.A. Communicated by Prof. Hull, LL.D., 

 F.R.S., F.G.S. 



The rock classed on maps of the north of Ireland as Old Bed 

 Sandstone is of two kinds — the lower and larger portion|chiefly con- 

 glomerate of felstone, schist, grit, passing into sandstones, cut off by 

 a fault on N. and N.W. from metamorphic rocks, and resting near 

 Pomeroy, in the N.E., on fossiliferous Lower-Silurian. Associated 

 with these are sheets of lava, probably submarine, from which the 

 above felstone-pebbles have been derived; these are porphyrite. Fear 

 Recarson, also, are vesicular melaphyres, whether contemporaneous 

 or intrusive is doubtful. There is also an intrusive granite, which 

 alters the sandstones into quartzites, and is prior to the upper series, 

 now generally held to be basement conglomerate of the Carboniferous. 

 This, formerly coloured as Old Red Sandstone, is unconformable 

 with the other, which it much resembles. The lower conglomerates 

 have been considered Lower Old Red Sandstone ; the author showed 

 that these bear great resemblance to parts of the Dingle series of the 

 south of Ireland. In the north of Ireland the upper conglomerates 

 are succeeded by sandstones, and these by Carboniferous Limestone. 

 The author regards the upper conglomerates as representing the Upper 

 Old Red Sandstone of Waterford (the Kiltorcan beds of the south not 

 being identifiable in the north), and the overlying sandstones as 

 the equivalents of the Carboniferous shale and Coomhola grit, and, 

 in Scotland, of the Calciferous Sandstone. 



10. "A Review of the Family Vincularidae, recent and fossil, for 

 the purpose of Classification." By G. R. Vine, Esq. Communi- 

 cated by Prof. P. M. Duncan, M.B., F.R.S., F.G.S. 



11. u On the Zones of Marine Fossils in the Calciferous Sandstone 

 Series of Fife." By James W. Kirkby, Esq. Communicated by 

 Prof. T. Rupert Jones, F.R.S., F.G.S. 



12. " The Glaciation of the Orkney Islands." By B. N. Peach, 

 Esq., F.G.S., and John Home, Esq., F.G.S. 



In this paper, which forms a sequel to their description of the 

 Glaciation of the Shetland Isles, the authors, after sketching the geo- 

 logical structure of Orkney, proceeded to discuss the glacial pheno- 

 mena. From an examination of the various striated surfaces, they 

 inferred that the ice which glaciated Orkney must have crossed the 

 islands in a north-westerly direction, from the North Sea to the 

 Atlantic. They showed that' the dispersal of the stones in the Boulder- 

 clay completely substantiates this conclusion ; for in Westray this 

 deposit contains blocks of red sandstone derived from the island of 

 Eda, while in Shapincha blocks of slaggy diabase, occurring in situ 

 on the south-east shore, are found in the Boulder-clay of the north- 

 west of the island. Again, on the mainland, blocks of the coarse 

 siliceous sandstones which cross the island from Inganess to Orplin 

 are met with in the Boulder- clay between Honton Head and the 

 Loch of Slennis. 



Moreover, they discovered in the Boulder-clay the following 



