COLLECTED IN DUTCH NEW GUINEA. 



277 



and I do not think them worthy to rank as a subfamily, much less as a family, as some 

 authorities have proposed. After the exclusion of Pseudomugil, a genus with four 

 species from Australia and New Guinea that has usually been associated with them, 

 but is probably much more nearly related to the Celebesian Telmatherina, Melanotoenia 

 and its allies form a natural group, as characterized above. 



Certain zoogeographical generalizations have been supported by evidence derived 

 from the supposed distribution of the genera and species; hence the importance of a 

 systematic revision of the group. 



As the result of the study of a large series of examples I have arrived at the 

 conclusion that all the forms described from Australia under no less than seven generic 

 and fourteen specific names belong to a single widely distributed and variable species, 

 Melanotcenia nigrans Richards, and this also includes four supposed species described 

 in recent years from New Guinea and the Am Islands. 



From its wide range in Australia, from the north coast southwards to the Swan 

 River, the Fincke River, the Murrumbidgee River, and Sydney, as well as from the fact 

 that some of the records seem to indicate a marine habitat {e. g. Gulf of Carpentaria, 

 Coast of Swan River), we may infer that the sea has aided in its distribution. 



It may be noted that structurally this species is the prototype of the whole group, 

 that it is the only species common to Australia and New Guinea, and that the other 

 New Guinea species are all generically distinct from it; consequently this group of 

 fishes furnishes no evidence as to the date or extent of a former land-connection 

 between Australia and New Guinea. 



There appear to be only nine well-established species, which may be arranged in 

 seven genera ; the probable derivation of the latter from a type similar to Melanotcenia 

 may be expressed diagrammatically : — 



Centraiherina. 



Chilatherina. 



Anisocentrus. 



Glossolepis. 



Shadinocenirus, 



Rhomhosoma. 



Melanotcenia. 



•li-^ 



