114 THE LAKE-BASINS OF IARCONN AUGHT. 



and-shell debris blown up into them by the wind, 

 each heavy gale forming a new layer, which the 

 vegetation binds more or less together, and preserves 

 froin removal by subsequent winds. In some places 

 the lagoon has become filled with a peaty soil, and 

 as the south-east of Ireland seems to be gradually 

 sinking, the sea is nearly imperceptibly moving back 

 the sand-ridge, so that in places the sand-ridges are 

 found to have a peaty foundation under them. 1 



Bars and ridges of gravel or sand like those we 

 have described, can only form near the end of a bay, 

 or at the margin of the sea. There are, however, other 

 accumulations, such as the already-mentioned banks 

 and mounds of gravel and sand in the valley of Kyle- 

 more. These would appear to be comparable to the bars 

 at present forming in straits, or any other place where 

 two tides or currents meet ; and if the land hereabouts 

 was lowered 350 feet, the tides would flow and ebb 

 through the valley of Kylemore, and form similar bars 

 and mounds to those that at present exist. 



That such conditions obtained during the " Esker 

 sea " period, appear proved by our finding in the 

 different valleys of larconnaught, and also in Clare, 



1 Althougli this coast may be now sinking, it appears not improbable 

 that a short time since it may have been rising, as part of the ridge 

 that now margins the mudlauds of Wexford Harbour is said to have 

 been formerly off the mouth of that haven, and was marked on the 

 charts as dangerous shoals. The estuaries on this coast deserve a much 

 more careful examination than has yet been given to them. 



