74 



OUR COMMON BRITISH FOSSILS. 



Leaving out other fossils, the student may find at 

 the Wren's Nest, or in the quarries opened in the lime- 

 stone, abundance of such corals as Favosites Gothlan- 

 dica, F. polymorphci) etc., and various species of such 

 characteristic Silurian corals as Omphyma (in great 

 abundance), Cystifhyllum, Porites, Heliolites, Palceocy- 

 clus, Columnaria, Halysites (the well-known and very 

 plentiful " chain-coral "), Strombodes, Cyathophyllum, 



Fig- 57. CaryopJiyllia, a recent British Coral (natural size). 



etc. Not only is there an abundance of species of 

 fossil corals, simple and compound, but of genera and 

 species as well. Compared with this wealth of Zoan- 

 tharian life, our modern seas are quite poverty-stricken. 

 All that even the warmer waters of our Devonshire 

 and Cornish coasts can now support are a few pretty 

 but insignificant corals, the largest of which is Caryo- 

 phyllia, a genus which first appeared in the seas of the 



