TERTIARY ARCHHELENIS 



DR. A. E. ORTMANN 

 Carnegie Museum, Pittsburgh, Pa. 



The Archhelenis-theory of von Ihering has now re- 

 ceived so much support from various sides that we may 

 regard it as firmly established with regard to its general 

 correctness. Stated in broad terms, this theory assumes 

 a former land connection between Africa and South 

 America, which is rather old. This connection is the last 

 remnant of a large southern continental mass (South 

 Atlantis, Gondwana-land), which existed since the be- 

 ginning of the organic history of the earth (Cambrium), 

 which was broken to pieces at different times, and the 

 remnants of which are now found in Australia, India, 

 Africa and Brazil. The separation of Brazil from Africa 

 was the last step in the dismemberment of this old con- 

 tinent, an event which is placed by most writers toward 

 the end of the Mesozoic era, although some have admitted 

 the possible continuation of Archhelenis into the begin- 

 ning of the Tertiary. 



Recently, von Ihering has tried to fix the time of the 

 disappearance of the connection between Africa and 

 Brazil more exactly, and arrived at the conclusion that 

 Archhelenis persisted at least through the Eocene. He 

 discusses the question chiefly in connection with his 

 studies on the marine fauna of the Patagonian beds, 

 which he regards as Eocene. 1 Comparing this fauna with 

 the contemporaneous Tertiary faunas of the rest of the 

 world, he discovers certain facts, which, according to 

 him, can not be explained except by the assumption that 

 Archhelenis was still in existence at the beginning of 

 the Tertiary. 



Bering, H. von, "Les Mollusques fossiles du Tertiaire et du Crj§tac4 

 supeneur de 1 'Argentine, " Anal. Mus. Buenos Aires, 14, 1907. 



237 



