326 Scientific Proceedings, Royal Dublin Society. 
Achill, skirting the north shore of Clew Bay. This road, at about 
three and a half miles from Mulrany, passes between low cliffs 
of Old Red Sandstone, which are, as we have said, about 100 feet 
above the sea. Immediately bordering the road on the south 
side is a small peat bog, with a turf cutting in which we found 
some shells; and beyond the bog there lie in tumbled ruin many 
blocks of sandstone partially concealed by peaty deposit and 
vegetation. In the hollows under these blocks we found great 
numbers of shells. The cliffs themselves were much undercut, so 
as to form deep, narrow recesses from which we scooped out many 
limpets. On the north side of the road we found under the clifis 
similar deep excavations, and in front similar scattered blocks. 
Here also we found large shell-deposits, a portion of a crab’s 
claw, and some fish-bones, the latter like the shells of quite 
modern type. The fish remains included portions of a Wrass’s 
skeleton. 
Last Easter (1908) one of us made further explorations in the 
immediate district, and found shell-deposits at 150 feet, at 300 feet, 
and at about 750 feet above sea-level. In each case the shells lay 
in horizontal pockets or clefts, at the base of cliff-like rock-terraces 
of Old Red Sandstone. Thelargest deposits were found in recesses 
at the base of a rocky cliff 300 feet above the sea, and about a 
quarter of a mile to the north of the little village of Dooghheg. 
Here many shells are exposed on the surface in hollows beneath 
the cliffs, and others occur deep in the narrow clefts, beneath the 
rocks, from which we were able to extract them by means of a 
small long-handled rake. Near Lough Ard on the mountain 
slope, 700 to 750 feet above sea-level, shells were obtained in 
large numbers in similar positions. 
We record these observations because we think that the 
occurrence of large deposits of shells at heights varying from 100 
to 750 feet above sea-level, on the hills to the north of Clew Bay, 
demands explanation from geologists. 
The shells of course differ entirely from those obtained in drift, 
which are scattered and broken, while these are unbroken and 
grouped in vast numbers. Moreover the types are not mixed, for 
all the shells are littoral. It is impossible to believe that the 
shells were carried to their present position by birds. ‘Their 
number, their unbroken condition, and their presence in deep 
