238 THE AUSTRALIAN HYDROMEDUS.E, 



IV. SUBOEDER TRACHOMEDUS1NJE. 



Von Lendenfeld, 1884. 



TRACHOMEDUS^ CLAUS. 



HYDROMEDUS^ WHICH ARE MEDUSiE, AND ARE PROPA- 

 GATED SEXUALLY WITHOUT A CHANGE OF GENERATION AND 

 WITHOUT FORMING POLYPOID ZOOIDS. MEDUS-2E W T ITH 

 ENTODERM AL ACUSTIC CLUBS. 



SCHEMA : 



Ovum 



I 

 Medusa 



I 

 Ovum 



or : 



Ovum 



! 



Medusa Ovum 



Medusa 



I 

 Ovum. 



17. FAMILY TRACHOMEDUSID^E. Von Lendenfeld, 1884. 

 Trachomedusae. Haeckel. 

 The Gonads are developed in the walls of the Radial Canals. 



1. SUB- FAMILY PETASNLE. 

 Petasidse. Haeckel. 

 With 4 Radial Canals, with long tube shaped stomach. Acustic 

 clubs free or in vesicles on the margin of the Umbrella. 

 Petasus. Haeckel. 

 Dipetasus. Haeckel. 

 Petasata. Haeckel. 

 Petachnum. Haeckel. 

 Aglauropsis. F. Miiller. 

 Gossea. L. Agassiz. 

 Olindias. F. Miiller. 



