THE FAIRY SAILOR AND HIS COUSINS. 121 



Is not this an enemy from which the lesser tenants of the 

 deep would flee without pausing to raise the question of 

 supremacy ? These monsters maintained the ascendency 

 till the introduction of fishes, toward the close of the Upper 

 Silurian, or later. Their decline dates from this epoch ; and 

 when the voracious fishes of the Old Red Sandstone and 

 the Carboniferous Limestone came upon the stage of being, 

 the orthoceratites dwindled away. Their last representa 

 tives barely saw the rising of Mesozoic Time. Not a trace 

 of a straight plain-chambered shell has been found in any 

 of the rocks above the Trias. They fulfilled their end in 

 creation and retired. Other carnivorous animals of a high 

 er order were better adapted to the advancing state of the 

 earth s preparation. Garpikes appeared. A new dynasty 

 arose, to be in turn overthrown by the dynasty of the Me 

 sozoic reptiles. 



F 



