280 MICACEOUS SCHIST. 



This rock is found in Isla, in the Garvelock 

 Islands, in Rannoch, and elsewhere, alternating 

 with the general series, and it must therefore he 

 considered as a regular bed. In other cases, 

 possibly, it may be analogous to the local con- 

 glomerates that are found at the meeting of two 

 rocks of different kinds. 



I must add to this enumeration a variety 

 which is, in a certain degree, distinct from any 

 of the former, although it can only be considered 

 as an accidental modification. Any one of the 

 preceding may put on this aspect, which occurs 

 in the vicinity of granite. The ingredients are, 

 in this case, so strongly cemented as to be inse- 

 parable, and, sometimes, almost undistinguish- 

 able. It is not enumerated with the siliceous 

 schists, because it has not been the practice so to 

 do ; but it bears a strong analogy to the primary 

 varieties of these. 



Under the preceding heads, as far as I have 

 observed, every variety of micaceous schist may 

 be arranged ; although the diversity of aspect is 

 so great as to convey an idea of the existence of 

 an infinitely greater number. These diversities 



