POISSONS ,,- 



1 4, 



sing chieilv northern Brazil and Guiana, which he calls • Archibrazil », resp. « Ar< hi r uyana », 

 or « Archiamazonas ». This lutter part was connected — in Mesozoic times — with West Africa 

 by way of St. Helena, and he calls this continental mass « Archhelenis ». 



a The connection of Archiplata with Antarctica explains its relations to Australia and 

 New Zealand. » 



2. — Sur la même Faune australe miocène, M. W. B. Scott, Professeur à l'Université 

 Princeton (Etats-Unis), écrit, à son tour, ce qui suit, ait point de vue continental (') : 



« The earlier Miocène (Santa Cruz) mammals of that continent are totally différent from 

 those of the northern landmasses, so much so that the corrélation of horizons becomes a matter 

 of extrême difficulty. The hoofed animais ail belong to orders unknown in the north, Toxodontia, 

 Typotheria, Litoptema, and the principal constituents of the fauna are immense numbers of 

 Edcntates, Marsupials and Rodents, with several platyrrhine monkeys. No artiodactyls, perisso- 

 dactyls, proboscidians, Condylarthra or Amblypoda, neither Insectivora, Cheiroptera, Carnivora 

 or Creodonta are known. The Edentates are ail of the specifically South American type, sloths, 

 armadillos and the like. The Rodents also are very much like those which still characterize 

 the région, though most ot the gênera are distinct ; they are ail Hystricomorpha, neither 

 squirrels, marmots, beavers, rats or mice, hares or rabbits occurring among them. The Primates 

 are typically neotropical and evidently belong to the platyrrhine group. The Marsupials are 

 partly opossums, more or less like those which still inhabit the Americas, and, what is at first 

 sight very surprising, partly of Australian type. The latter contain both diprotodont forms 

 (Abderites, Acdestis, Epanorthus) allied to the existing Hypsiprymnus and polyprotodont gênera 

 (Protoproviverra, Cladosictis, etc.), the affinity of which to the Dasyuridœ is clear. » 



« The fauna of the succeeding « Patagonian formation » is of exactly the same gênerai 

 character and contains no new éléments, but merely somewhat more advanced gênera of the 

 same orders, while the Marsupials are much reduced in numbers and importance. » 



u In the Pliocène (Monte Hermoso) appear the first traces of the union with North 

 America in the présence of mastodons, horses, tapirs, deer, Hamas and true carnivores, and from 

 that time till far into the Pleistocene the intermigrations between the two continents kept up 

 until a large number of common types had been established. » 



« The présence of numerous marsupials or distinctively Australian type in the Tertiary 

 rocks of South America is very strong évidence indeed that both ot those continents were con- 

 nected with the Antarctic land. » 



« That thèse marsupials indicate a land connection between South America and Australia 

 can hardly be denied, for none of them hâve ever been found in any northern continent, o 



3. — Ainsi, MM. Ortmann et Scott réclament, tous deux, pour des raisons différentes 



/. L'isolement de la portion méridionale de l'Amérique du Sud ; 



2. Une Antarctide réunissant la Patagonie à l'Australie ; 

 pendant le Miocène. 



Ces exigences s'accordent avec la Biogéographie actuelle des Notothemidœ, - et, parti- 

 culièrement, avec celle du Bovichthys diacanthus, cas, autrement, difficile, comme nous le verrons 

 dans un moment. 



(i) W. B. Scott. Antarctica Palœontology. (Science. 1896. Vol. III. p. 3o8). 



