1866.] JTJKE8 OLD EED SANDSTONE AND DEVONIAN. 325 



the mass fragments of plant-stems occur, either as impressions on 

 the sandstones, or as flattened stems with a thin coating of coaly 

 matter. Little seams also of carbonaceous matter sometimes appear 

 between the beds. 



Beds of greenish shale set in near the top of the Old Eed Sand- 

 stone, the uppermost one being capped by a bed of grey " fucoid " 

 shale, which is taken as the base of the Lower Limestone Shale. 

 There are, however, here not more than from 10 to 20 feet of actual 

 black shale before we come up to the compact grey limestone. The 

 limestone beds are well shown in the low cliff on both sides of the 

 promontory as far as the extremity of the Head, a distance of two 

 miles and a half. They are much bent and broken, dipping in vari- 

 ous directions, although never at angles exceeding 30°, and rarely 

 above 10° or 15°. There is a belt of magnesian limestone (one of 

 the many places in which the Carboniferous Limestone is dolomi- 

 tised) about 400 yards wide, crossing the promontory before reaching 

 the extremity of the Head ; but except in that space, the cliffs are 

 crowded with fossils, all of them of species which are known to occur 

 in the Carboniferous limestone elsewhere, as will be seen on refer- 

 ring to the lists by Mr. W. H. Baily, given in the Explanation of the 

 Sheet 167, &c., of the Maps of the Geological Survey of Ireland. 



3. Waterford. — Opposite the Hook Point, on the western coast 

 of Waterford Harbour about Dunmore, the Old Red Sandstone 

 spreads in a nearly horizontal position over an isolated area six or 

 seven miles long by about two broad, resting unconformably on 

 Lower Silurian rocks, which rise steeply out from underneath it on 

 the west and north. 



Two or three other isolated patches of similar size lie, like cakes 

 of Old Eed, on the highly inclined Silurians on both sides of the 

 harbour further north, and in the southern angle of County Kilkenny, 

 between the rivers Suir and Barrow. 



These isolated patches are obviously pieces spared by the denu- 

 dation that has removed the rest, and uncovered the Silurian rocks 

 around them. They serve to connect the Old Eed Sandstone of Hook 

 with the persistent mass of it which takes the ground north of the 

 city of Waterford. 



Immediately to the north-west of the city of Waterford, on the 

 south side of the river Suir, are some black slates, in which Di/plo- 

 grapsus pristis and GraptolitJius tenuis are abundant. They dip north- 

 west at 60° and 70°. On the northern side of the river the slates 

 and grits of the Lower Silurian formation are of a greener hue and 

 more siKceous appearance, and are unfossihferous, but dip in the same 

 direction, at 70° or 80°. 



These beds are well shown in the cuttings in the cliffs at the back 

 of the houses by the railway station ; and on their upturned edges 

 lie great beds of br»wn and red quartzose conglomerate, dipping north- 

 west at 10° or 15°. 



These are the basal beds of the Old Eed Sandstone; which may be 

 followed in one direction to the river-bank, on the other side of which 

 they reappear striking to the west into County Waterford ; while in 



