P. Mamair fy J. Reid—On the Old Red of Scotland. 217 



making these upper rocks represent a succession from Cambrian 

 through a Lower Silurian series, while the lower members represent 

 a still older group of rocks, some of which may be the deep- 

 sea equivalents of the p re-Cambrian conglomerates of Loch 

 Torridon and other parts of the west coast, an idea which 

 I pointed out some years ago. 



Table of the Altered Clastic Hocks of the Southern Highlands 

 of Scotland. 



V.— Pal^ontological Considerations on the Old Eed Sandstone 



of Scotland. 



By Peter Macnair and James Reid. 



The Ganoidian Fishes of the Old Red Sandstone. 



HOWEVER paradoxical it may appear, we have reason to believe 

 that the occurrence of so-called ganoidian fishes — of a fresh- 

 water type— in the Old Eed Sandstone affords the strongest evidence 

 in favour of its marine origin. That recent representatives of the 

 ganoids of the Old Eed Sandstone inhabit rivers and lakes of the 



