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THE AMERICAN NATURALIST [Vol.XLIV 



I fully accept the facts of the faunistic relations of the 

 Patagonian beds, as laid down by von Ihering. Yet I do 

 not believe that they demonstrate the necessity of assum- 

 ing the existence of Archhelenis at that time, but, on the 

 contrary, I believe that they point just to the opposite, 

 namely, that at the time when the Patagonian beds were 

 deposited (in the early Tertiary— it does not matter, for 

 the present purpose, whether we regard the beds as 

 Eocene or younger) the connection between Brazil and 

 Africa must have disappeared, and that there must have 

 been a deep ocean in its place. 



Of the relations of the Patagonian fauna to other 

 faunas, the following are' mentioned by von Ihering as 

 most important (p. 76 ff.) . 



While the Patagonian fauna in general is very peculiar, 

 and consists preeminently of southern (antarctic) ele- 

 ments, yet there are certain affinities to Tertiary faunas 

 of the northern hemisphere. But there are hardly any 

 relations to North America, and the few affinities with 

 northern faunas are rather with the Indo-European 

 fauna. This, of course, means that the Indo-European 

 forms, which may be regarded as constituting resem- 

 blances with the Patagonian fauna, are not found in 

 North American Tertiaries. Von Ihering believes that 

 these peculiar conditions are to be accounted for by the 

 existence of a land barrier between the North and the 

 South Atlantic, which prevented a migration of North 

 American marine forms to Patagonia, while there was a 

 possibility for Patagonia to receive Indo-European types 

 from the Indian ocean along the eastern coast of Africa 

 and the southern coast of the Atlantic land-connection 

 (Archhelenis). 



While I do not doubt the correctness of the view that 

 Patagonia did not receive the Indo-European elements 

 of its fauna by the direct way, from the Mediterranean 

 across the Atlantic, I think, the fact of the absence of 

 these forms from North America is not correctly under- 

 stood and interpreted by von Ihering. If Archhelenis 



