ACTINOZOA. 



241 



MESOZOIC, CAINOZOIC, and EECENT COKALS, ^-hich 

 occuE m MORE THAN ONE GEOLOGICAL Peeiod — Continued. 



Chcetetes passes up into the Trias. With this 

 exception no genus of Corals survives the Paleozoic 

 epoch except, perhaps, Isis, of which doubtful in- 

 dications have been met with in rocks of very 

 ancient date. 



No Triassic genus of Corals has recent represen- 

 tatives. Of genera which occur in the Jurassic 

 series seven still survive. Fourteen recent genera 



