THE CARBONIFEROUS SERIES. 15 



are found fossil plants and shells, such as characterize these 

 strata in the basin of the Clyde. The structure, indeed, is 

 quite analogous to that of the Clyde basin. Limestone does 

 not occur at the base of the system, nor does it occupy any 

 determinate place in it, but is found throughout the whole 

 series of beds in repeated alternation with the sandstones and 

 shales. These alternations are seen in section on the sea 

 shore along the east border, on the hill-side between Corrie 

 and Brodick, along the high grounds on both sides of Glen 

 Cloy, in Clachan Glen, Glen Scorodale, and other water 

 channels issuing westward ; and in the Ben-leister burn above 

 Lamlash they descend almost to the bottom of the glen. On 

 this ground we refer the whole of the sandstones of the 

 southern division of the island to the carboniferous series. 

 The alternations in question are not seen, it is true, on the 

 Corriegills, Whiting Bay, or Kildonan shores, nor do they 

 appear among the sandstones of the South End ; but such 

 massive strata of red sandstone as appear along the east and 

 south shores are common in the carboniferous system, and 

 form indeed everywhere its prevailing member. They are 

 conformable to the strata inland, in perfect sequence with 

 them, of the same mineral structure, and therefore referable 

 no doubt to the carboniferous system. They may thus be 

 correlated with the calciferous sandstones of the Ayrshire 

 coast, upper members of the system, described by the geolo- 

 gists of the Ordnance Survey ; but this can only be regarded 

 as a provisional arrangement until the discovery of fossils 

 shall give us more certain data for classification. 



9. The fragments imbedded in the conglomerate, both of 

 this age and of the Old-Red system, are mica slate from a 

 distant source, the ordinary slate adjoining, and quartz of 

 two varieties, of which one is the common white quartz, 

 forming veins in the slate, and the other a peculiar resinous 

 quartz, of a cinnamon colour, not found in Arran, but closely 

 resembling certain varieties found on the west coast, and in 

 Islay and Jura. The resinous variety is rounded and polished, 



