Vol. 52.] THE KILDARE INLIER. 589 



and on the average about | mile broad. In this small area there 

 are exposed rocks of Ordovician and probably also of Silurian age, 

 while red micaceous sandstones and quartzose conglomerates, referred 

 by the officers of the Geological Survey to the Old Ked Sandstone 

 Series, protrude in places from beneath the Carboniferous Limestone, 

 and rest on the upturned edges of the older rocks. 



The area is easily noted from a distance, as it is formed of four 

 prominent hills arranged in a line running roughly in a north-east 

 and south-west direction, and rising some 400 to 450 feet above the 

 level of the surrounding country. Of these four hills, that farthest to 

 the south-west is Grange Clare Hill, then comes Dunmurry Hill, then 

 Grange Hill with the Chair of Kildare as a projection, while finally 

 to the north-east lies the Hill of Allen. The whole of the sur- 

 rounding country is deeply covered with drift, the junction of the 

 Carboniferous Limestone and Old Red Sandstone with the beds of 

 the inlier being never seen. 



"We shall describe first the sedimentary and afterwards the 

 igneous rocks ; and since the stratigraphical succession is best seen 

 on Grange Hill we shall first describe that hill, including with it the 

 Chair. 



The complete absence of cliff or stream-sections has rendered the 

 correlation of the beds a matter of some difficulty. 



III. The Sedimentary Rocks of Grange Hill and the 

 Chair oe Kildare. 



The lowest beds are seen on the northern slopes of Grange Hill. 

 They consist of olive-green gritty shales dipping south-east at an 

 angle of from 60° to 70°. Associated with them are some more 

 definitely gritty bands which pass occasionally into a conglomerate 

 containing well-rounded pebbles of shale and grit, often some | inch 

 in length. These gritty shales pass up into an andesitic ash which 

 can be traced all along the foot of -the hill to a point north-north- 

 west of the top of the Chair. This ash has proved very fossiliferous 

 just behind Grange Hill House Cottage, where it is exposed some 

 10 feet below the base of the overlying igneous rock, under which 

 it dips to the south-east at an angle of about 60°. At this point, 

 moreover, it is of a distinctly more gritty type than elsewhere. 



From this ash we obtained the following fossils : — 



'o 



Pbiacopora Orai/a, Nich. & Eth. 

 Orthis porcata, M'Coy 



alternata, Sow. 



flabeliulum, Sow. (very common) 



ccUHgramma t Sow. 



te.sf/(d/)i(iria, Sow. 



Strophomena deltoidea, Conrad 



expanm, Sow. (common) 



Leptfena (Plectambonites) 8ericea,8ow. 

 Calymene senaria, Conrad (very 

 common) 



Calymene Blumenbachii, Brongn. 

 Ctenodonta varicosa, Sow. (very 



common) 

 Orthonota parallela, Hall 

 Modiolopsis expa?isa, Portl. 

 Raphistoma aqualis, Salt. (very 



common) 

 Holopella, sp. 



Murchi.ionia sulcata, M'Coy 

 Pleurotomaria cf. claustrata, Linclstr. 



