168 FORMATION OF CORAL REEFS. 



Coral wall continues its steady progress ; for 

 here the lighter kinds set in, — the Madrepores 

 (p. 107), the Millepores, and a great variety of 

 Sea-Fans (p. I'm, below) and Corallines, and the 

 reef is crowned at last with a many-colored 

 shrubbery of low feathery growth. These are 

 all branching in form, and many of them are 

 simple calciferous plants, though most of them 

 are true animals, resembling, however, delicate 

 Algae more than any marine animals ; but, on 

 examination of the latter, one funis them to be 

 covered with myriads of minute dots, each repre- 

 senting one of the little beings out of which 

 the whole is built, while nothing of the kind 

 is seen in Algae. 



I would add here one word on the true nature 

 of the Millepores. long misunderstood by natu- 



ralists, because this type throws light not only on 

 some interesting facts respecting Coral Reef-, es- 

 pecially the ancient ones, but also because it tells 

 us something of the early inhabitants of the globe, 

 and shows us that a class of Radiates supposed 

 to be missing in the primitive creation had its 

 representatives then as now. 



