236 THE AUSTRALIAN HYDROMKDUB^, 



SCHEMA : 



Ovum 



I . 

 medusoid bud 



I 

 Spiralzooid Polype Polypostyl 



entwined Hydrorhiza, basal plate 



I 

 First Polype 



I 

 Ovum 



Hydractinia. Van Bemeden. 



Coppinia, Hincks 1 



III. SUBORDER HYDROCORALLIJSLE. 



Moseley. 



ALIMENTARY ZOOIDS WITH FEW VERTICILLATE, CAPITATE 

 TENTACLES. HYDRORHIZA FORMING A DENSE CALCAREOUS 

 SKELETON WHICH ALSO INVESTS THE POLYPES. GROUPS 

 OF MACHAPOLYPES, IN THE FORM OF TENTACULAR ZOOIDS, 

 SURROUND THE ALIMENTARY POLYPES. 



Ultimately generative Zooids are probably Medusae 



SCHEMA (?) : 



Ovum 



I 

 Medusa 



I 

 Machopohjp Polype 



Hydrorihiza 



I 

 First Polype 



I 

 Ovum. 



