4 THE NATURALIST IN AUSTRALIA. 
the only other two discovered living representatives, Lepidosiren paradoxus and 
Protopterus annectens, inhabit respectively the rivers of Brazil and those of tropical 
Africa. The true Australian Barramundi, Osteoglossum Leichardti, also an inhabitant 
of certain Queensland rivers, typifies a family group having but a limited number of 
living representatives, which agree almost precisely with the Dipnoi in the singularity 
of their geographical distribution. In this relationship Osteoglossum possesses even 
more significant alliances. For while Ceratodus is represented in Brazil and Africa 
by allied, but, at the same time, very distinctly differentiated generic types, the 
rivers of Brazil and Guyana yield a species, Osteoglossum bicirrhosum, referable to 
the same genus as the Queensland fish. A third species, O. formosum, inhabits the 
rivers of Bornea and Sumatra, and a fourth form, O. Jardinei, has been discovered and 
chronicled by the writer within the last few years as inhabiting those rivers of North 
Queensland which debouch upon the Gulf of Carpentaria. The ally of Osteoglossum 
in the African continent is Heterotis niloticus, common to the Upper Nile and various 
West African rivers. The most remarkable member of family Osteoglosside is, 
however, the huge Arapaima gigas, which shares with Osteoglossum bicirrhosum a 
Brazilian and Guyanan habitat. It is notable as being the largest known of Teleostean, 
let alone fresh-water fishes. It not unfrequently exceeds a length of 15 feet. 
The little native trouts, referable to the genus Galaxias, of the Australian 
fresh-water streams, and so-called for their somewhat trout-like shape and usually 
spotted ornamentation, are additional witnesses in evidence of the theory of an exten- 
sive Antarctic Continent, wherein, in this instance, New Zealand is distinctly involved. 
Of the numerous species of Galaxias known to science, an approximately equal 
number are found in New Zealand and in Australia and Tasmania respectively. Three 
species of the same genus are peculiar to the fresh-water lakes and rivers of Chili and 
Patagonia, while one species, Galaxias attenuatus—as attested to by Dr. Gunther, 
“Catalogue Fishes,” Vol. VI., p. 211—-occurs without any recognisable specific dis- 
tinctions in the four widely-separated areas of Tasmania, New Zealand, the Falkland 
Islands, and the southern parts of South America. No stronger evidence could perhaps 
be adduced in demonstration of the pre-existence of a vast homogeneous Antarctic 
Continent than that yielded by this little fresh-water generic group. 
The fresh-water fishes of the family Haplochitonide, including the Australian 
and New Zealand genus Prototroctes, or so-called cucumber mullets or graylings, and 
the allied South American genus Haplochiton, yield corresponding though less abundant 
testimony in the direction recorded of Galaxias. Within recent years a species of 
