Fig. 11. A, Diphyes campanulata (natural size). B, a group of 

 appendages (cormidium) of the same Diphyes (magnified). (After 

 C. Gegenbaur.) a, axis of the colony; wi, nectocalyx (swimming 

 'organ'); c, sub-umbral cavity of nectocalyx; v, radial canals 

 of nectocalyx; o, orifice of nectocalyx; t, bract (protective 

 'organ'); n, siphon (nutritive 'organ'); d, gonophore (re- 

 productive 'organ'); i, tentacle (defensive 'organ'). 



