JF. B, Wright — Submerged Forests in Donegal Lakes. 117 



be seen in the position of growth, but in three of the cases the outlet 

 of the lake is through a peat-bog, so that no conclusion regarding 

 the failure of the outflow during the growth of the trees could be 

 based on them. In the remaining four (Loughs Bannus, Avehy, 

 Drumgun, and Afurnagh) the outlet is over rock or boulder-clar, but 

 the last-named is open to exception, as it is extensively margined 

 by peat, through which it may possibly at one time have had a lower 

 drainage. 



Lough Bannus is situated on the Donegal Road, 2 miles W.S.W. of 

 Pettigo. Its surroundings are shown in Fig. 1. It lies among 

 drumlins, and has its outflow to the east over boulder-clay, the stream, 

 however, soon entering a little rocky valley without any great fall. 

 The outlet has been lowered by artificial cutting to the extent of 

 about two feet, and tliere is an abandoned shore-line about the same 



■ drumlini., 



Fig. 1. Map of Bannus Lough, showing the position of the submerged tree 

 stumps and the contours of the surrounding ground. 



height above the water surface round the south side of the lake. It is 

 clear, therefore, that in its natural state the lake was some two feet 

 or so higher than at pi'esent. Tree stumps, submerged even at the 

 present day, have been observed in two places, one on the northern 

 shore and one on the eastern. The latter appear to be in the position 

 of growth, the former are more doubtfully so. 



Lough Avehy (Fig. 2) is on the Ballintra Road, 4| miles west 

 of Pettigo. Its southern and western shores are formed of boulder- 

 clay, and its northern and eastern of crystalline schists. It has 

 cut fairly steep scarps, five or ten feet high, in the boulder-clay 

 on the south side ; but these are no longer being eroded, for the 

 level of the lake has been lowered from two to three feet, apparently 

 by artificial drainage, and there is an abandoned shore-line at about 



