2SO 



HYDROID POLYPES 



Fig. 58. — Diphyes campanulata. 



A, the entire colony, natural size, showing stem (a) bearing groups of 

 zooids (') and two swimming bells (w, m), the apertures of which are 

 marked 0. 



B, one of the groups of zooids marked e in A, showing common stem, 

 {a), hydranth («), medusoid {g), bract {i), and branched tentacle or 

 grappling line \i). (From Gegenbaur.) 



