HASEMAN, GEOGRAPHICAL D I ST RIB UTION IN SOUTH AMERICA 83 



the mid-Atlantic whirlpool and ocean currents. They may have origi- 

 nally migrated down the North American coast from Europe, and it is 

 even more probable that the observed affinities are due to similar evolu- 

 tion in similar environments. If this is not true, why have so many 

 species remained similar to the Miocene forms of Europe ever since the 

 supposed land-bridge disappeared or from before Tertiary times ? When 

 and where did this bridge exist? Are not the corals of the North and 

 South American coasts also similar ? If not, why not ? 38 



GONDWANA FLOKA 



Similar deposits of sandstones, clays, shales and bowlder till are found 

 in Brazil, South Africa, India and Australia. These deposits are chiefly 

 Permian and contain among other fossils the characteristic lower Gond- 

 wana flora (Gangamopteris or Glossopteris flora). The identity of the 

 Gangamopteris flora, along with many fossil and living genetically re- 

 lated animals found in Africa and South America, has led to a widely 

 accepted belief that these continents were originally connected. This old. 

 land-mass has been designated Gondwana and is thought by some to have 

 extended across the Atlantic between either Brazil or Guiana and Africa. 

 Others have ignored this connection and have maintained a southern 

 connection by way of the Antarctic Islands. 



The Gangamopteris flora, according to I. C. White and David White, 

 has been found six meters above the crystalline floor of the coal fields of 

 southern Brazil. At this level, only Gangamopteris obovata was found. 

 The next higher level, 55 meters above the granite floor near Minas, 

 Santa Catharina, contains Rosellinites gangamopteridis, Hysterites bra- 

 siliensis, Phyllotheca griesbachi, P. mulleriana, Glossopteris browniana, 



Vertebraria ?. . ., Gangamopteris obovata, Arberia minasica, 



Derbyella aurita, Noeggerathiopsis liislopi, Cardiocarpon seixas and 

 Cardiocarpon moreiranum. 



These species belong to the early typical Gangamopteris or lower 

 Gondwana flora. The same genera, and in many cases identical species, 

 are found in the Ecca shales of South Africa, in the coal associated 

 with marine lower Permian of New South Wales and Tasmania and in 

 the Karharbari beds of India. The same flora is found in the lower 

 Coal Measures of Argentina and the Falkland Islands. Only much later, 

 in the upper Permian of the northern part of Eussia, are any of these 



38 If Archhelenis existed, I fail to see how the rivers could have been arranged on it so 

 that only one family of crabs, two families of fishes and a few fresh-water and land 

 mollusca took advantage of it, when the same theory assumes that the coastwise streams 

 of eastern Brazil have been barriers to at least part of this fauna. 



