518 THE AMERICAN NATURALIST [Vol. XL1II 



mann. 18 In place of the present Southern continent he 

 thinks that toward the end of Mesozoic times, there 

 existed the old Brazilian land (Archiplata), an Antillean 

 continent (including the West Indies and Venezuela) and 

 also the Chilean coast range. These three land masses 

 were separated from one another by wide oceans. Just 

 before the close of the Secondary era the Antillean conti- 

 nent, and with it Venezuela and even the Galapagos 

 Islands, became united with western North America, the 

 latter being then still detached from eastern North 

 America. When Venezuela in early Tertiary times at 

 last became fused with the other larger South American 

 land masses, the interoceanic connection across Central 

 America had severed it from North America. 

 Under such geographical conditions the Wvoming 



<mlv have 

 portion of 



■sent Southern . 



That South America owes its origin to the union ot 

 several independent land masses is so clearly indicated by 

 the existing fauna of the continent, that a similar evidence 

 should also be revealed by a study of its rocks and fossils. 



The geology of South America is unfortunately as yet 

 little known. Yet even such a cautious observer as Pro- 

 fessor Suess 19 ventured to suggest, on strati graphical 

 grounds, that an arm of the sea may have penetrated right 

 across the continent in Cretaceous times. The archaic 

 rocks of eastern Brazil and Guiana certainly were then 

 raised above the sea, since the younger formations appear 

 to be superimposed with great regularity further and 

 further to the west of this ancient formation. Dr. 



