SILURIAN PERIOD 37 



strong af&nities with trilobites and half-made king-crabs ; 

 and it is not hkely that any of their descendants ever figured 

 as true fishes. 



The appearance of fishes attested the rise of a new power 

 in the sea ; and, as after-events proved, it was not to be a 

 marine power only, but had wonderful destinies beyond its 

 native element. 



Long had the waters embraced sponges, corals, sea-liUes, 

 molluscs, and creatures in crusty armour variously wrought ; 

 and now they nursed a life higher and more resourceful 

 than any of these. Different indeed was the land with its 

 humble verdant growths, and populated by animals of no 

 higher grade than insects. 



