(GNEISS. 259 



difficult to distinguish the felspar from the quartz, the 

 specimens are easily confounded with common mica- 

 ceous schist. 



D. A schist of foliated mica, with interspersed 

 and large irregular crystals of felspar ; the quartz being 

 scarcely discernible. 



E. An undulated coarse schist, consisting of 

 large gTains of felspar and of quartz closely packed 

 and connected by the smallest possible quantity of 

 mica. Occurs in the argillaceous series of the High- 

 land southern border in company with micaceous schist 

 of the same structure and appearance. 



It may be added that the whole of this sub- 

 division presents transitions from gneiss into 

 quartz rock and into micaceous schist. Where 

 the felspar is red they are easily distinguished: 

 when white, it is much more difficult to recognize 

 them. I may also add that hornblende is, as in 

 the first subdivision, an occasional ingredient, 

 and that this subdivision also, is occasionally por- 

 phyritic. 



This variety occurs abundantly on the west 

 coast of Scotland, in Rannoch, and in the middle 

 Highland districts of Atholl arid Badenoch. 



s2 



