FISHES— REGAN. 41 



Tertiary land-bridges to account for all cases of this sort would reduce the oceans to 

 a few puddles. 



Much has been made of the distribution of the Galaxiidae and Haplochitonidae, for 

 some time regarded as fresh-water fishes found in Southern Australia and Tasmania, 

 New Zealand, and the southern part of America. It is now known that Galaxias 

 attenuatiis, the only species common to all these regions, breeds in the sea. In the 

 " Scotia " report 1 have shown that these two families are Salmonoids related to the 

 Osmeridae, and their marine origin may be regarded as certain. Like the northern 

 Salmonoids they are establishing themselves in fresh water, and it is interesting to note 

 that Galaxias occurs at the ('ape and even in New Caledonia, where, like the Trout of 

 Algeria, it remains as the witness of a glacial epoch. 



None of the families of true fresh-water fishes of either South America or Africa 

 occurs in Australia, except the Osteoglossidae, a generalised and ancient type. Even in 

 this case the relationship is not with America or Africa, but with Asia, Scleropages 

 comprising one species from Queensland and New Guinea, and one from Borneo and 

 Sumatra. 



Thus neither marine nor fresh-water fishes support the theory that the Antarctic 

 continent connected America with Australia during the Tertiary Period. This being 

 the case, I have been led to examine somewhat critically the other zoogeographical 

 evidence in support of this theory. Some of this is derived from the similarity of 

 marine faunas, or from the distribution of fresh-water organisms that may have had a 

 marine origin. Of more importance are the land animals, and Dollo, in his monumental 

 report on the " Belgica " fishes, comes to the conclusion, " (''est I'Antarctide Tertiaire 

 de M. Osborn — ou une Antarctide analogue, indispensable pour les Marsupiaux et 

 Miolania — qui explique le mieux la. Biogeographie des Poissons Antarctiques et Sub- 

 antarctiques." Unable to accept this for the Fishes, 1 have looked into the question of 

 the Marsupials and Miolania. 



Marsupials. 



It has been suggested that ( 'aenolestes and the extinct Patagonian members of the 

 Epanoi'thidae may be related to the Australian group Diprotodontia. This is by no 

 means generally accepted, and several authorities believe that the Epanoi'thidae may 

 have been derived from a primitive Didelphoid type which has evolved a diprotodont 

 dentition independently. This view is supported by the fact that the Epanorthidae are 

 eleutherodactyle, whereas the Australian Diprotodonts are syndaetyle.* 



It has recently been shown by Gidley f that the Multituberculates are "Dipro- 

 todonts," so that Marsupials of this type date back to the Triassic, and even if they be 

 monophyletic, their occurrence in Australia and South America loses its significance. 



* Thomas, Proc. Zool. Soc. 1895, p. 870 ; Gregory, Bull. Amer. Mus. xxvn, 1910, p. ill. 

 t Proc. U. 8. Nat. Mus. xxxvi, 1909, p. 611. 



