Old Red Sandstone. 113 



geologists, well known to those of the Geological Survey, 

 who mapped the ground, that some of the valleys of 

 Cumberland are of older date than the deposition of the 

 Old Eed Sandstone, and standing on the ground it was 

 impossible for me not to fed the idea, that Mell Fell 

 and Little Mell Fell look like, and may be, the relics 

 of an old moraine, shed from a glacier of Old Red 

 Sandstone age, that flowed down a valley far older than 

 that of modern Ullswater, and long before the special 

 hollow in which the lake lies was formed. The 

 mountains were much higher than now, for since then 

 they have undergone an immense amount of denudation. 



In Scotland fishes are more or less found in all the 

 broader districts occupied by Old Red Sandstone, but it 

 was chiefly in the north, in Caithness, and on both sides 

 of Cromarty and Moray Firths, that Hugh Miller made 

 his wonderful discoveries of fossil fishes of many 

 species. They are found generally in bituminous 

 schists and flags with occasional nodular concretions, 

 and lie in various minor horizons among red and varie- 

 gated sandstones and conglomerates, which contain the 

 remains of many fish of the genera Diplopterus, 

 Coccosteus-) PterichikyS) Diplacanthus, Osteolepis, 

 Glyptoloemus, Dipterus, Holoptychius, Cephalaspis, 

 besides Crustacea, such as Pterygotus 9 and the small 

 bivalve Estheria Murchisonice. (Fig. 26.) 



Most of the genera belong to a sub-order of Ganoid 

 fish called Crossopterygidce by Huxley, from the fringe- 

 like arrangement of the fins, a sub-order several species 

 of which are still living in the rivers of Senegal and in 

 the Nile. 



I have specially mentioned these circumstances, for 

 the purpose of keeping before the mind of the reader 

 the broad fact that the Old Red Sandstone, as a whole, is 



I 



