CONGLOMERATE ROCKS. 581 



and is of partial occurrence. It is found in 

 Canna and elsewhere. 



These rocks, as far as can be determined, are 

 secondary, but they may also be primary when- 

 ever the rocks to which they are attached can be 

 proved to belong to this class. They pass into 

 the red sandstone at Oban and at Dunkeld, and 

 thus form general conglomerates. 



SECOND DIVISION. 



Consisting of two substances or rocks united 

 in modes analogous to the varieties of the First 

 Division. 



A. Serpentine and limestone, or calcareous spar: 

 local. 



This includes the ornamental substance known 

 by the name of verde antico, already mentioned. 

 It is necessarily primary. The ordinary varieties 

 are connected with serpentine, or lie between that 

 rock and limestone. 



The situation of the verde antico is not 

 known. Anglesea affords an accessible example 

 of a corresponding nature. 



B. Fragments of argillaceous schist with lime- 

 stone. 



