462 



Evolution and Distribution of Fishes 



passed westward by St. Paul, Tristan, The Falklands and 

 ■Magellan to Chile. Derivatives of these passed northward 

 to Africa; or became modified, often in remarkable manner, 

 for deep sea life; or, as breaking up of the Southern conti- 

 nent went on, they reached the most southern marine habi- 

 tats now known for fishes. 



13. The final breaking up of the Southern Continent 

 probably took place in late Miocene or early Pliocene time, 

 when the most pronounced elevation of the Andes, and of 

 the great Eastern Chain of Africa took place. 



14. Through extensive faulting and depression of the 

 entire South Continent its place is now covered by a deep 

 sea, except for the few isolated — often volcanic — island- 

 peaks that still mark the line of the sunken mass. 



15. The species of Galaxidae and Aplochitonidae, that 

 now inhabit elevated lakes or streams, have been carried 

 to these elevated regions, not by ascent of ancestral in- 

 dividuals, but by earth-movements that have simultaneously 

 raised large areas of land, along with the fishes that in- 

 habited the lakes or streams of such land, before elevation 

 took place. 



Fig. 71a. Galaxias truttaceus. Enlarged after Giinther. 



