138 FORMER LAND CONNECTIONS. 



Both the floras and faunas, particularly the latter, indicate 

 such a union, for the modern tortoises of Madagascar are like the 

 gigantic fossil forms of Egypt and the Victoria Nyanza, while we 

 have also an instance in the Malagasy hippopotamus. This island 

 has yielded a number of species of extinct giant lemurs, a family 

 still living not only there, but in Central Africa and Malaysia as 

 well, hence the name "Lemuria" given to this land-bridge connect 

 ing Madagascar, their supposed centre of origin, with Africa and 

 the Malay region. 



Another view, based upon the fact that the Lemuridac are 

 well represented in the Eocene of Europe, is that they originated 

 there, entered Madagascar from the west, and became isolated in 

 that island, their development therein being largely due to the 

 practical absence of Carnivora. On the other hand Dr. II . F. 

 Standing has shown that among the sub-fossil lemurs of Madagascar 

 there are closer analogies with the monkeys of South America than 

 with those of the Old World. Moreover, since they possess 

 degenerate characters the parent stock probably originated on the 

 Afro-American land-mass. 



Severing of South America from Africa. 



Accordingly, turning to the Argentine, we find a marked 

 ; geological parallel with the Swellendam-Heidelberg districts of the 

 Cape, inasmuch as estuarine variegated marls of Cretaceous Age 

 rest in valleys cut in the equivalents of the Cape fold-ranges. The 

 ocean did not penetrate here until Eocene times, and the fauna 

 is that of the now-developing South Atlantic Ocean, typically 

 Antarctic and neither Pacific nor North Atlantic in its facies, thus 

 proving that the Argentine-Brazilian section of Gondwanaland still 

 •extended considerably further eastwards towards Africa. 



In fact, since North Atlantic forms do not make their appear- 

 ance on the South American coast until the Pliocene, it has to be 

 presumed that the latter was divided from Africa at the end of 

 the Cretaceous by an extremely narrow strait. Such a view 

 receives weighty support, first, from the absence of Cretaceous beds 

 along the two opposed coast-lines, between the Argentine and 

 Bahia and between the Cape and Angola respectively, and secondly, 

 from the fact that the strata of that epoch represented further to 

 the north in each case possess faunas not only very closely related to 

 one another, but of the type characterisng Morocco, Tunisia, and 

 Portugal — a North Atlantic assemblage in fact. 



Apparently the breach that was developing between Africa 

 and South America in the Upper Cretaceous commenced to broaden 

 from the north, allowing the North Atlantic to enter and ulti- 

 mately to join up with the already formed South Atlantic-Indian 

 Ocean. 



That the two continents were separated by water at the com- 

 mencement of the Tertiary is shown by the marked dissimilarity 

 between the mammalian faunas of the two countries, the four 

 typically Ethiopian orders being unrepresented in South America 

 for example; on the other hand the analogies displayed between 

 -the monkeys of the latter region and the Madagascar lemurs require 



