430 THE GEOGRAPHICAL DISTRIBUTION OF THE SCYPHOMEDUS^E, 



Of those fourteen species there are four known as coming from 

 more than one place. None of the Australian Medusa? are found 

 beyond Malabar. Two are found in the East Indian Archipelago, 

 and also on the Coast of North Australia. The northern kinds 

 have in general a wider distribution than the southern. New 

 Zealand species seem perfectly isolated, the three belonging to 

 New Zealand not having been found in any other place. 



Generally speaking we can say that the distribution districts 

 are very limited, and that three districts, for the moment at least, 

 perfectly independent of one another can be distinguished in the 

 Australian waters. These are — New Zealand with its three 

 species ; South-east Australia with five, and North Australia with 

 five. 



The district of New Zealand is still very little known. Within 

 the two others we find local as well as transgressing species, 

 which, although they have at present only been found in two 

 places, probably exist in the parts lying between these. Therefore 

 we must accept as a fact that Pseudorhiza exists between 

 Adelaide and Melbourne, and Cambressa mosaica between Mel- 

 bourne and Sydney. 



Although our knowledge of the Australian Medusa is very 

 limited still I do not doubt that the three distribution-districts 

 seen on the table do really represent the facts. The cause of the 

 development of these three well defined distribution-districts is to 

 be found in the currents. 



The New Zealand Medusae, which, from the grounds alluded 

 to above, have surely come from the east coast, belong to the 

 New Zealand equatorial current, and this current might possibly 

 carry the Medusa to the southern polar sea but never to the 

 Australian coast. A current flows from Tasmania towards New 

 Zealand. But as till now, no Medusa? from Tasmania have been 

 described, it is impossible to know what influence this current 

 may have on the distribution of the New Zealand Medusa?. But 

 any connection between the Fauna of Bass' Straits and that of 

 New Zealand cannot take place as may be clearly seen from the 

 map. 



