The Raised Beaches of hiishowen. 281 



they threw them overboard in shallow water, where they were 

 seen crawling about some time afterwards. Whether the species 

 thus introduced into Lough Swilly still flourishes there is a 

 nice point for inquiry ; but its occurrence in the Fort Stewart 

 raised beach shows that it formerly lived in these waters. 



Going northward along the shore, Boulder-clay holds the 

 ground till Inch is reached. Along the shore eastward of the 

 old castle, which rises picturesquely on a high knoll of quart- 

 zose grit, are traces of low raised beaches. Westward of the 

 castle, at Mill Bay, two sea-terraces rise, one behind the other, 

 in the pasture near the shore, like green waves on the sward, 

 to heights of about twelve and fifteen feet above high water, 

 the ground falling away a little behind each. No section is 

 exposed, but the ground is very shelly. On the north side of 

 Inch, near the church, where raised beaches are marked on 

 the Survey map, there are beds of sand and gravel up to eight 

 feet above high water, but no features of interest are 

 observable. 



Next day I left the hospitable house of my host, Prof 

 Leebody, in the small hours of the morning, and took the 

 6.20 train to the favourite watering-place of Buncrana, prettily 

 situated on the shores of Lough Swilly. A brisk walk over 

 the sand-hills that stretch southward revealed nothing of 

 interest, and after breakfast I tramped nine miles northward 

 to Mamore Gap, a picturesque pass formed by an old line of 

 fault across a rugged mountain-ridge of quartzite that stretches 

 on both sides of the entrance of Lough Swilly. The view as 

 one passes through the Gap is very beautiful — the sands of 

 Lenan Bay to the right ; below, a sandy and boggy flat 

 dotted with cottages, and beyond that the huge mass of 

 Dunaff" Head ; further to the eastward, the rugged outline 

 of North Inishowen, and Malin- Head ; and beyond all, 

 the illimitable ocean. A steep descent led to Lenan Bay, 

 where the westerly winds have swept the shifting sands up 

 the adjoining hill-side to a height of 150 feet. Down on 

 the beach, the sand has become cemented by some natural 

 process, and masses of it stand out in weathered torrs six to 

 ten feet high, looking like reefs of schist. Passing over the 

 low ground (marked raised beach on Geological Survey map) 

 lying behind Lenan Head and Dunaff Head, I found at 

 Rockstown Harbour a good example of what is no doubt the 



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