FOSSIL CORALS. 59 



They are compound corals, whose shapes are modified 

 by the manner in which they grew, so that some are 

 polygonal, or many-sided, and others oval or round. 



Fig. 37. Syringifora ramulosa, a common Carboniferous limestone Coral. 



The most remarkable of these tabulate fossil corals 

 are Heliolites, Favosites, the pretty " chain-coral " 



Fig. 38. Heliopora ccerulea, a recent Alcyonariai. Coral. 



(Halysites\ Syringipora, etc. It will be seen from 

 Fig. 36, which shows a magnified section of a very 



