RED CORAL. 29 
when spread out are extremely beautiful. The young are 
at first free swimming (III and IV). Another curious 
form is the organ-pipe coral, formed of upright tubes. 
Il WF 
Fic, 27.—Red coral (C. rubrum). 1, Branch showing polyps closed and ex- 
panded: 4, mouth. II. Section of branch: 2, mouth ; m, stomach ; 
Jf, canals; 4, irregular canals; P, hard axis. IIT and IV. Free-swim- 
ming embryo, showing the cilia, or oars. 
