134 



ANTHOZOA I STONY CORALS. 



in the accompanying figure (fig. 75). The particular arrange- 

 ment of the radiating plates of the Madrepore (shown at the 

 top of each stem) is the result of the 

 form of the soft structures by which 

 it was deposited; and wherever we 

 see a structure of this kind in coral, 

 whether upon a large or a small 

 scale, we may infer that it was formed 

 by an animal nearly allied in structure 

 to the Sea- Anemone. Of the stone 

 depositing coral -animals, a large 

 number are often* associated in a com- 

 pound structure, as in fig. 76 ; this 

 consists of a stony tree-like stem and 

 branches ; but instead of the soft ani- 

 ^ matter k e i ng contained in its 

 interior, as in the Hydrozoa, it usually forms a kind of flesh 



Fig. 76. STEM OF CORAL. 



that clothes the surface, and connects together the different 



