BY .7. DOUGLAS OOILRY. 65 



closely approach it, but in other biological Classes a much more 

 intimate geographical relationship between these Regions may be 

 discerned.* 



Several theories have been enunciated to account for this 

 singular disti'ibution of a family of fresh-water fishes in such 

 widely separated regions as western South America, south-eastern 

 Australia, and South Africa. Apparently the most favoured of 

 these theories, as it is also the most natural and the most strongly 

 supported by recent facts, is that, at- some remote period of the 

 world's history, there existed a great austral continent, which 

 has now largely disappeared beneath the surface of the ocean and 

 which extended northwards on the one hand through Tierra del 

 Fiiego to the southern and south-western parts of South America, 

 on the other through Tasmania to south-eastern Australia, and 

 possibly also to New Zealand and South Africa. 



So far as Australia and America are concerned I see no reason 

 to doubt that they were at one time connected at their southern 

 extremitfes by a belt of land stretching across the south pole, and 

 that the antarctic continent so formed enjoyed a mild and equable 

 climate, and supported a large and varied flora and fauna, the 

 remains of which are abundantly visible in both to the present 

 day, but especially in Australia, where forms of animal life, 

 elsewhere extinct or nearly so, still constitute characteristic 

 features in the faunic aspect, among which may be mentioned 

 the MarHupialin among Mammals, the Struthionids among Birds, 

 certain Lizards such as Chlamydosaurus, and Fishes such as 

 Neoceratochis. 



With regard to the claims of New Zealand and South Africa 

 to a post-mesozoic junction with Antarctica the testimony is by 

 no means so convincing, in fact the weight of evidence clearly 

 points to the conclusion that at no more recent time was there 

 any intimate connection between them, while tliei'e are manj'^ 

 indications that the distance separating them was not so wide as 



* For references see Hedley, Proc. Koj'. Soc. N.S. Wales, 1S95, p, 3, 

 note 1. 



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