io The Irish Naturalist January, 



in this rock are chiefly species of Favosites, and also Haly sites 

 catcnularia, the latter being very common in the corresponding 

 limestone at Portrane. Covering the limestone at Kiln Point, 

 and banked up against the cliff-face all the way round from 

 here to Seal Hole, is a coarse conglomerate, consisting of large 

 and small blocks of limestone, andesite, shale, &c. Many of 

 the limestone blocks are very fossiliferous, and yielded to 

 Messrs. Gardiner and Reynolds, Favosites, Halysi+es catenu- 

 laria, Heliolites megastoma, and Raftncsquina expansa. The 

 matrix of this rook is distinctly ashy, and the writer agrees 

 with the above-mentioned authors that this conglomerate is 

 not comparable with the crush-conglomerate of Portrane, but 

 represents an ashy conglomerate of sedimentary origin. 



Silurian shales of a brown colour occur at Saltpan Bay, and 

 at the extreme east of the outcrop, on the top of the cliff, are 

 much fractured, forming a land-slide. In the castle grounds 

 the same rocks outcrop, also at Talbot's Bay, Carnoon Bay, 

 and north of the Old Red Sandstone at Broad Bay. At 

 Talbot's Bay the beds are very much contorted, and contain 

 purplish bands, the rocks at Carnoon Bay resembling them, 

 and both forming probably a slightly different horizon in the 

 Silurians to that of the Saltpan Bay slates, though there is no 

 evidence as to their relative horizons if they really are different. 

 Orthis biforata has been obtained in some baked slates at 

 Talbot's Bay, the later intrusion of the andesite having effected 

 this change in the sediments here and at some other points on 

 the island. 



Some massive beds of Old Red Sandstone occur at Broad 

 Bay, forming a striking feature at this point, as well illustrated 

 in Plate 5. By some curious oversight no mention of this 

 rock appears in the otherwise very detailed account of the 

 .sedimentary rocks of L,ambay by Messrs, Gardiner and 

 Reynolds. Three or four massive beds of coarse conglomerate 

 passing into red shale locally, on which the remains of glacial 

 striatums are clearly visible, occur on the south side of the 

 bay. The beds are steeply tilted, with a slight twist, so that 

 the dip increases gradually from west to east. The total thick- 

 ness of the beds is not above 50 feet, and it is noteworthy that 

 they contain no pebbles of the local igneous rocks, though 

 they are clearly later in date. The explanation may possibly 

 be that they have been faulted down to their present position 



