"254 S. J. JOHNSTON. 



Of all the trematodes known from Australian birds only 

 four have been referred to new genera, viz., Platynotrema 

 biliosum Nicoll, P. jecoris Nicoll, Allopyge antigones mini 

 and Austrobilharzia terrigalensis mini. The remainder 

 have not only been referred to known genera, but are, for 

 the most part, pretty closely related to known species 

 occurring in other parts of the world. In some of the birds 

 which are migratory or have a very wide range the same 

 trematode has been recorded as occurring in them both in 

 Australia and in Asia, Europe or other parts; for instance 

 the Echinostomid Chaunocephalus ferox Rud. has been 

 recorded both from Asia and Australia as parasitic in the 

 Jabiru, Xenorhynchus asiaticus, a stork that ranges from 

 India through Southern Asia and the East Indies to Nor- 

 thern Australia. Patagifer bilobus Rud. has been recorded 

 several times in Australia from Platalea regia and Pele- 

 gadis falcinellus and was originally described in Europe as 

 a parasite of the European Platalea leucorodia. With one 

 exception, all the trematodes known from Australian birds 

 are either identical with, or more or less closely related to 

 parasites of birds in other parts of the world. 



It is a remarkable and significant fact that all these 

 relatives of the Australian forms should find birds as their 

 hosts. And further than this, the bird-hosts of similar 

 forms are almost in every case birds of a similar kind. 



Of the fifty-one trematodes of Australian birds mentioned 

 in the foregoing table, thirty find their nearest relatives in 

 trematodes parasitic in birds of the same family, ten in 

 birds of a closely related family, and seven in birds which 

 cannot be considered closely related to the Australian bird- 

 hosts, while three are so constituted that they do not seem 

 to have any near relatives amongst known trematodes. 



In the case of the first group and perhaps also of the 

 second, it may be considered that the pairs of related 



