THE GEOGRAPHICAL DISTRIBUTION OF THE 

 AUSTRALIAN SCYPHOMEDUSvE. 



By R. von Lendenfeld, Ph.D. 



There is extremely little known of the physical conditions of the 

 Australian Seas, but this little will suffice to explain the peculiar 

 geographical distribution of the Rhizostomse in these waters. 



Of all the different kinds of Medusa? the Rhizostomse can be 

 preserved most easily. They are also more easily noticed by 

 travellers than the more delicate and smaller forms of the other 

 groups. I have myself seen Rhizostomous Medusa? from the deck 

 of a large steamer so clearly, that with a little imagination I could 

 have given a description of them, so striking are these creatures on 

 the open sea ! 



There are therefore from the more inaccessible parts of the 

 surface of the earth relatively more Rhizostomous Medusa? known 

 than others, and for the same reason the Rhizostoma considered 

 alone gives a better idea of the geographical distribution of the 

 Medusae than could be obtained by considering the whole class, 

 as in the latter case those in the more accessible places would be, 

 in proportion, too numerous. 



I shall therefore confine my remarks to Rhizostoma?. 



The chemical constitution of the sea, the quantity of common 

 salt contained in it, and the proportion in which other salts are 

 found, are all at present unknown. (1) The knowledge of the 

 currents which are most impoi^tant for our enquiry is in a far 

 higher state of development. 



(1.) The result of the observations taken during the Voyage of the 

 Challenger, have not yet been published. 



