220 



OUR COMMON BRITISH FOSSILS. 



growth of fossil Polyzoa, many of them allied to, if 

 not identical with, existing kinds, such as Cellepora^ 



Fig. xZ(i.—Diastopo}U vcntrkosa (highly magnified). 



Membranipora, Hornera, etc. Others arc locally ex- 

 tinct, and can only be found in warmer seas. Near 



Fig. 187. — Cells o{ Dtastopora OoUtica 

 (highly magnified). 



Fig. 188. — Fasciciilarla aiirantiuin 

 (Coralline and Red Crags). 



Orford the young geologist will find plenty of round 

 balls, which, when split open, reveal a radiated struc- 



