362 



MAJOR A. H. DWERRYHOUSE OK THE [vol. lxxix, 



drainage. This bifurcation of the channel indicates that a lobe of 

 ice still penetrated Glenshesk as far as this point, and stood at a 

 level of about 500 feet, thus closing the outlet of the pre-existing 

 northern valley, and allowing the waters to cut the southern channel. 

 A slight retreat then opened the northern branch, which was rapidly 

 deepened and widened by the powerful stream from Glenmakeeran 

 Lake. 



The Altiffirnan gorge comes to an end abruptly on entering 

 Glenshesk, and is continued by a normal V-shaped valley com- 

 parable in magnitude with the existing stream. The change in 

 character of the valley takes place at a level slightly above 400 feet,, 

 which has already been indicated as that of Glenshesk Lake and 



Fig. 2. 



■Capture of the Owencam River by an overflow-channel 

 from the lake in Glenmakeeran. 



GLENMAKEERAN 



,o*V<< 





[The deserted valley is seen on the left, and Garneighaneigh 

 in the background.] 



of its great overflow the Inver channel. The cutting power of the- 

 Altiffirnan stream was neutralized so soon as it entered the waters 

 of the lake, and the gorge ends abruptly at that level. The small 

 Y-shaped continuation is the work of the existing post-Glacial 

 stream, which enters the gorge from the north just above the 

 bifurcation. 



The upper terrace in the Glenmakeeran valley can be correlated 

 with the level of the intake of the Owencam channel, and the 

 largest of the terraces in the Corratavey and Glenmakeeran valleys 

 with that of Altiffirnan Glen. 



A still further retreat opened a channel in the Townland of 

 Glish, across the spur between the valleys of Glenmakeeran and 



