Ill 



COELENTERA TA 



41 



B 



FIG. 19. Aurelia aurita developing Medusae. 



Scyphistoma before transverse fission. B, Scypliistoma undergoing fission. Several 

 Ephyrae have already floated off. Below the last Ephyra which is to be set free, 

 the Scyphistoma is developing the tentacles characteristic of the Hydroid. (It 

 is unusual for constrictions to appear below these as were seen in this specimen.) 

 C, One Ephyra, side view. D, One Ephyra seen from below. 



