\\\ 1 
INTRODUCTION. 
ii innnher of uiitliors, including, among others, Amcgliino * * * § , lllanford f, Boulcnger [}i, 
J.ydekker^, Neumayr||, Ortmann Scott** * * §§ , Siicss'j’f’, and von IheringJJ. These 
writers, basing their arguments on many diverse kinds of evidence, all seem 
to ari'ive at the general conclusion that a land-connection did exist between 
Africa and Soutli America throughout at least most of the Secondary period and 
may have persisted into the Lower Tertiary. Concerning the precise position 
of this land-connection, and whether it may have existed at more than one point, 
there is some diversity of opinion, but these differences do not seem to be of 
any great importance compared with the general agreement that there must have 
been such a connection. Speaking generally, it appears that (1) probably in 
Jurassic times Africa and South America formed a continuous land-mass ; (2) in 
the Cretaceous period the sea encroached southwards over this land, forming 
what is now the Soutli Atlantic. How far this depression had advanced southwards 
at the end of the Secondary period is not clear, but it appears certain that the 
final separation of the two continents did not take place till Eocene times, and 
that there may have been a chain of islands between the northern part of Africa 
and Brazil which persisted even till the Miocene 
On the assumption that this series of events did happen, there is little difficulty in 
accounting for most of the peculiarities in the distribution of the various groups. 
'i'liLis, to mention only a few instances, the presence in both continents of the Hystrico- 
morphine Rodents, of Chelonians of the family Peloniedusidae, and of the Fishes of the 
family Cichlidie is at once accounted for. So also is the presence in the Santa Lruz 
* La Argentina al travi's de las Ultimas Epocas Geologicas (Buenos Aires, 1S97). Also “Linea 
Filogenelica de los Proboscideos,” Anales AIus. Nac. Buenos Aires, vol. viii. (1902) p. 19 ; and “ Les 
Edentes fossiles de Prance et d’Allemagne,” Joe. cit. \ol. xiii. (1905) p. 175. 
t Presidential Address to the Geological Society, 1S90. 
t Presidential Address to the Zoological Section, Brit. Assoc. (South Africa, 1905). 
§ A Geographical History of Mammals (1890), p. 127. 
ii Erdgeschichte (1890), p. .370. 
^ “ Geographical Distribution of Preshwater Decapods and its Bearing on Ancient Geography,” Proc. 
Amer. Phil. Soc. vol. .\li. (1902) p. 267. 
** Reports of the Princeton University Expeditions to Patagonia (1890-1899) — Palaeontology, vol. v. 
pt. ii. (1905). 
tt Das Antlitz der Erde, vol. ii. (1888). 
Xt “ On the Ancient Relations between New Zealand and South America,” Trans. New Zealand Instit. 
vol. XXV. (1891) p. 431. 
§§ Por evidence of the probable existence of shallow water across this region, perhaps as late as the 
IMioccne, see Gregory, Quait. Journ. Geol. Soc. vol. li. (1895) p. 3U0. 
