16 ANNALS NEW YORK ACADEMY OF SCIENCES 



continuous with Australia. The sea traversed northern Brazil and sepa- 

 rated the Guiana highlands plus the West Indies (Arehiguiana) from the 

 rest of South America, but it was connected with both Asia and Europe. 

 Africa was not connected with Asia at that epoch. In 1911, he had made 

 many changes in his views. 



On the other hand, after a long detailed study of both the mollusca and 

 Crustacea, Ortmann has also maintained that an Archhelenis existed, but 

 he differs with von Ihering both in regard to its location and the time of 

 its disappearance. He believes that Archhelenis had already disappeared 

 before the beginning of the Tertiary (perhaps the early Cretaceous) and 

 that it connected Guiana and Africa. 



Eigenmann (1909) has tested the Archhelenis theory with the distribu- 

 tion of the South American fishes and has found no objections to it. In 

 fact, he states that the theory is quite useful in explaining irhe distribution 

 of certain families of fishes, especially the Characinidae and the Cichlidae. 



D. White (1907) in an excellent paper on the Gangamopteris flora 

 (Gondwana flora) of Brazil does not, however, favor the Archhelenis 

 land-bridge; he believes that an ancient connection (Permian) very 

 probably existed between South America, the Antarctic continent and 

 Australia or Africa. 



In Part V of Volume III of the Princeton Patagonia reports, Pilsbry 

 has summed up the distribution of non-marine mollusca of South Amer- 

 ica. His figure, page 632, indicates a former connection between the 

 region of Pernambuco, Brazil and South Africa. He is inclined to believe 

 that this connection disappeared by the end of the Cretaceous. He also 

 admits the probability of a connection by way of the Antarctic islands 

 with Australia, but he does not believe in a former isolation of the Guiana 

 highlands from those of Brazil. 



Schuchert (1911) also believes that the distribution of the brachiopoda 

 shows clearly not only the former existence of an equatorial Gondwana 

 across the Atlantic, but as well that its vanished Atlantic bridge still con- 

 trols the distribution of living forms. He is of the opinion that Gond- 

 wana probably existed until middle Eocene times. 



In the Age of Mammals (1910), Osborn re-states the widely accepted 

 belief in an Antarctic connection between South America and the Aus- 

 tralian realm, but he rejects a Tertiary Archhelenis. He thinks that this 

 connection is necessary in order to explain the great similarity which 

 exists between some of the fossil marsupials of Patagonia and the mar- 

 supials of the Australian realm. He also states that Matthew has rejected 

 both the Archhelenis and the Antarctica connections and now maintains a 

 northern origin of the southern fauna. 



