32 Proceedings of the Royal Irish Academy. 



CAELItf&FOED. 



Just a mile from Carlingford Castle, on the "n-ay to Greenore, 

 beyond a piece of brackish, water lying inside the railTvay, the road 

 makes a slight cutting through a raised beach for a length of about 

 one hundred yards. The only section is on the banks by the roadside. 

 There is to be seen a solid bed of oyster- shells, at between fifteen and 

 twenty feet above high-water mark, and for a few feet above and 

 below this layer are shell-bearing gravels. The deposit rests on 

 Carboniferous limestone. The shells found were — 



Ostrea edulis. v. c. Patella vuJgata. r. 



Cardium edtde. r. Littorina ohtusata. r. 



Tapes deciissatus. v. r. L. litorea. c. 



Geeencastle. 



On the side of Carlingford Lough opposite to that last-mentioned, 

 at the uttermost southern extremity of county Down, an extensive sea- 

 terrace is marked on the Geological Survey map. The only place 

 here which I have had an opportunity of examining is the shore from 

 Cranfield Point north-westwards. At Cranfield Point the great 

 deposit of granite detritus, which stretches round the southern slopes 

 of the !Mourne ^[ountains, forming in many places a thirty or forty- 

 foot clifE facing the sea, gives way to compact blue boulder-clay, with 

 large blocks of polished Carboniferous limestone. A little northward 

 the boulder-clay is capped by a few feet of marine gravels, eight or 

 ten feet above high-water mark, evidently a raised beach. Saxicava 

 rugosa, Patella vulgata, and Littorina litorea were collected, the first 

 in a limestone pebble. Further northward the Carboniferous lime- 

 stone crops out in low reefs on the shore. 



KlLlOUGH. 



At the head of Eillough Bay a low estuarine flat runs inland for 

 about a mile, at a level slightly above high water. Drain-cuttings 

 here show a foot of sandy clay, then a shelly layer, and under that 

 several feet (base not seen) of very fine, tough, piak and grey 

 laminated clay, without shells. The shell layer is made up of abun- 

 dance of Cardium edule, Tellina laUhica, Scroiicularia piper ata, and 

 Littorina litorea. Stretching across the lower end of this flat, a fine 

 raised beach faces the sea. The Ardglass railway runs along the top 

 of the raised beach, and cuts through it at KiHough Station. At this 



