SCYPHOMEDUS.E OF THE AUSTRALIAN SEAS. 



III. CLASSIS 



HYDROHEDim 



Sessil polpys or polyp 



colonies and free 



or rudimentary 



sessil Medusae. 



IV. CLASSIS 



SYPHONOPHORA. 



Tree 

 polymorph 



colonies. 



V. CLAS.SIS 

 ANTHOZOA. 



Sessil polyps or 



polyp colonies 



with internal 



tube. 



VI. CLASSIS 



SCYPHOMEDUS.E. 



Tree Medusre young 



stage polypoid, persistent 



in Leucernaridte 



without internal 



mouth-tube. 



Aphacellw. 



Without gastral 

 filaments. 



Phasellatce. 



With gastral 

 filaments. 



I. CLASSIS 



SPONGLE. 



Irregular, sessil, the 



principal organs 



mesodermal. 



PolypoineduscK. 



Polypoid, the prin- 

 cipal organs are 

 ectodermal or 

 entodermal. 



II. CLASSIS 



CTENAPHOR.E. 



With free external 



ribs and more 



highly developed 



mesoderm. 



Porifera. 



Sessil with collared 



entodermal cells in 



portions of the canal 



system ; 

 unsymmetrical. 



Cuidaria. 



Sessil or free without 

 such collared cells ; 



radially 

 symmetrical. 



Gastreadea. 



Sack-shaped, free- 

 swimming, with 

 simple ectoderm and 

 entoderm. 



