168 FORMATION OF CORAL REEFS. 
Coral wall continues its steady progress; for 
here the lighter kinds set in, — the Madrepores 
(p. 167), the Millepores, and a great variety of 
Sea-Fans (p. 167, 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 
Alege more than any marine animals; but, on 
examination of the latter, one finds 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 Alge. 
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 Reefs, 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. 
