by dr. r. von lendenfeld. 217 



Ordo Hydromedus^:. 



1. Subordo Hydropolypinse. 



2. ,, Hydromedusinse. 



3. „ Hydrocorallinse. 



4. ,, Trachoniedusinse. 



If we now classify the Hydromedusse according to the principles 

 set forth above we shall arrive at the following classificatory 

 system : — 



Schemas are attached to the diagnoses. The italics represent 

 stages which do not take up nourishment, the stages given in 

 ordinary print represent such which do. The schema's also show 

 the way in which the budding process alternates with the sexual 

 propagation. As the change of generation is caused by this 

 alternation on the one hand and influenced mainly by the phase 

 in which nourishment is taken up, these schema's will elucidate 

 the differences which are met with among the Hydromedusse in 

 this respect. 



The most important genera are mentioned. Genera which are 

 imperfectly known have been omitted. 



