Life in the Ancient Seas 317 



must he even that period! We think the pyramids 

 are old. But ohserve; the stones with which they are 

 built are obviously ages and ages older. 71iey are com- 

 posed of shells that had fallen to the bottom of an 

 ancient sea; the compacted masses hardened and were 

 lifted above the surface forming part of a great con- 

 tinent. Yet as old as must have been the nummulites 

 which formed that stone, there is strong evidence that 

 when the saurians swam the seas, this species of proto- 

 zoan was not yet in existence. 



