80 THE WANDERINGS OF ANIMALS [CH. 



Close affinity between fossil corals of the Antilles 

 and North- West Africa suggests a coast, at least 

 a shallow Atlantic sea. There is no affinity between 

 the marine shells of Argentina and those of the 

 Antilles ; this suggests land between Brazil and Africa 

 as an effective barrier, which in turn would account 

 for affinities of the terrestrial faunas. Most authorities 

 agree as to the existence of such a * bridge ' during 

 Mesozoic times, the only question is whether it lasted 

 long enough into the Tertiary to be available for 

 certain groups which have not yet been traced back 

 further than the Oligocene. Evidence is, however, 

 rapidly accumulating that not only families but even 

 many genera are much older than have been supposed. 



Instead of maps the schemes of diagrams intro- 

 duced on pages 84, 85 may serve to indicate in the 

 most condensed style the hypothetical configurations 

 in successive geological epochs. 



Straight lines mean continuity of land ; dotted 

 lines show transient connexion ; parallel lines indicate 

 separation by sea. The position of the present con- 

 tinents, etc. is expressed by their initials. Want of 

 space forbids any attempt to justify these broad 

 suggestions, but the chapter dealing with the present 

 and past range of selected groups of animals will 

 supply a considerable number of test cases. 



In its broadest outlines the history of the lands 

 and seas since the Carboniferous period may be read 



