RED CORAL. 



2 9 



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. 



FIG. 27. Red coral (C. rubruni). I. Branch showing polyps closed and ex- 

 panded : k, mouth. II. Section of branch: k, mouth; m, stomach; 

 /, canals ; A, irregular canals ; P, hard axis. Ill and IV. Free-swim- 

 ming embryo, showing the cilia, or oars. 



