Over a South Atlantic Continent 461 



some time, continuous with Juan Fernandez, the Galapagos, 

 and the Cocos Islands. 



8. Through extensive earth-shrinkage, faulting, and 

 volcanic activity from late Cretaceous and early Eocene 

 time onward, a large western section of this Archandean 

 continent was thrown deeply down, while the eastern part 

 was correspondingly elevated. Continued elevation in suc- 

 cessive sections gave rise to the eastern or palaeozoic range, 

 and the western or mesozoic range of the Andean chain, 

 according as the main masses of rock are exposed. 



9. The Geotridae of the Cyclostomata, also the 

 Galaxidae, and the Aplochitonidae are all probable descend- 

 ants from North American freshwater fishes. The two 

 latter families are intermediate between the Salmonidae 

 and the Esocidae, both of which are still mainly freshwater 

 fishes of the Northern Hemisphere. All three of these, by 

 migration along the swamps, rivers and lakes of the Arch- 

 andean continent, seem to have reached Fuegian-Falkland 

 Island Territory by late Cretaceous times. 



10. Eastward connection with Australia, Tasmania, 

 New Zealand and Norfolk Island was early established, 

 and by this the above fishes or derivative forms were intro- 

 duced. Such took place while as yet the American poly- 

 protodonts had not reached the east. When separation of 

 the N. Zealand area had been effected the migrating poly- 

 protodonts entered Tasmania and S. E. Australia, where 

 they still are most abundant and varied. They as well as 

 diprotodont descendants, spread westward and specially 

 northward in Australia, till they reached E. Indian Terri- 

 tory where the most highly evolved diprotodonts now are. 



11. By aid of rivers, lakes, and swamps the Geotridae, 

 Galaxidae, and Aplochitonidae gradually spread over the 

 entire South Continent from Fuegia to S. Africa, N. Zea- 

 land, and Australia, where various of their descendants 

 now are. So far as at present known they have been ob- 

 literated over Intermediate regions. 



12. While few of the freshwater fishes now known, 

 passed Westward from the N. Zealand and Australian 

 region, derivatives of primitive Notothenlidae and Lepto- 

 scopidae of freshwater habitat took to a marine life and 



