OF LOCHABER. 29 



suddenly, having the appearance, when viewed from that val- 

 ley, of a very singular breach, high up in the sides of its north- 

 western mountains. When viewed from Glen Collarig, the 

 Gap appears as in Plate III. fig. 1. (which was sketched from 

 point c in the map) ; and fig. 2. of the same plate, (which was 

 sketched from the point e in the map), shows its appearance 

 when looked at from Glen Roy. This Gap, is what, in my 

 former paper, I had conjectured to have a communication 

 with Glen Gluoy ; but the description I have just given of Glen 

 Collarig, shows this notion to have been erroneous. Glen 

 Gluoy has indeed no other communication with Glen Roy, 

 than by the high glen of Glen Turret, which I shall have oc- 

 casion to describe afterwards. 



The shelf which is marked all along its line with the figure 

 4 in the map, and which I said I was to designate as shelf Ath> 

 makes its first appearance high up on the side of Ben-y-vaan, 

 somewhat more than a mile to the east of Highbridge. From 

 this point it runs faintly eastward, sweeps up the Glen of Col- 

 larig, and crosses it just above some cottages, in the form of 

 an extended mossy flat, or rather gently inclined plane, which 

 has steep banks towards the bottom of the valley. It then 

 begins to return indistinctly back, on the western side of the 

 round hill of Bohuntine, increasing in strength as it embraces 

 its southern side ; and again winds round it in a northerly di- 

 rection, till it bends into Glen Roy. Plate II. will show this 

 part of the course of shelf 4th, and Plate III. fig. 1. will fur- 

 nish some notion of the mode in which it crosses Glen Colla- 

 rig. In this last Plate, shelf 2d and shelf 3d, are seen coming 

 from Glen Roy through the Gap towards the eye, and termi- 

 nating abruptly on both sides, as I shall afterwards explain 

 more particularly. 



The 



