52 



THE GEOLOGIST. 



ces. High up the valley of the Conway Dr. Buckland and 

 Mr. Bowman found extensive congeries of lofty mounds and 

 ridges of gravely one of them slightly stratified, which they 

 both thought must have been either diluvium or lateral rao- 

 rainesj modified however by water. 



From the falls of the Conway downwards nearly to 

 Llanrwst, the rocks on the right side of the valley ex- 

 hibit polished, striated and furrowed surfaces wherever it 

 has been laid bare, as well as boss-like outlines similar to 

 those in the beds of existing glaciers in the Alps. Below 

 Llanrwst, on the left side of the Conway, fluted and striated 

 surfaces were noticed in 1824 by Mr. Underwood, on the lofty 

 mountains between the Conway and the Ogwhyn, in a high 

 valley that discharges the water of Llyn Cwlyd, as well as on 

 the limestone of Great Brueshead, in front of the estuary of 

 the Conway. 



At the point where the Llugwy, which descends South- 

 West from Carnead Llewelyn, turns at right angles to the 

 S.E., a series of mounds of earth and gravel occur, covered at 

 their summits with hundreds of blocks of stone. The waters 

 of the Gwryd fall into the Llugwy near a lofty mound of 

 gravel resembling a terminal moraine, and just below this 

 jimction the rocks are rounded, striated, and polished. 



The right flank of the valley of the Ogwhyn near the vil- 

 lage of Bethesda presents abundant examples of polished 

 surfaces, fluted and striated in the direction of the valley. 



From the summit of the pass of Llanberis to the lower 

 end of the lake Llyn Padaru, the left side of the valley pre- 

 sents a succession of naked rocks rounded by attrition, and 

 striated. 



In the same way the table land immediately subjacent to 

 Snowdon on the W., presents numerous polished rocks. The 

 valley of the Llyfni exhibits a few striated surfaces at its 

 upper end, and a finer example of them occurs on the sur- 



