HASEMAX. GEOGRAPHICAL D1STRIB UTIOX IX SOUTH AMERICA 15 



been designated Archhelenis by von Ihering. Antarctica, another por- 

 tion of Gondwana, is the name generally applied to the south polar conti- 

 nent which is believed by some to have been connected with South 

 America and Australia and perhaps with Africa. 



2. The persistence of the continental shelves and the great ocean 

 basins. This view precludes the existence of former connections between 

 South America and the eastern hemisphere, but admits the North Ameri- 

 can connections with Eurasia. 



These two views involve not only the distribution of plants and animals 

 but the geology of the entire earth. They are not new, dating back in fact 

 nearly to the time (1857) when Sclater first placed geographical distribu- 

 tion in tangible form. In his scheme of distribution, the world was con- 

 sidered in six faunal regions, a scheme in which South America formed a 

 major part of the neotropical realm. 



In 1876, Wallace published two comprehensive volumes on the geo- 

 graphical distribution of animals. In these two most excellent volumes, 

 the genus was used more than the species as a. means of comparing faunal 

 regions, and it appears that such a comparison is more luminous than one 

 based on the species, for it is found that the generic characters are usually 

 more nearly paleotelic than the specific ones; moreover, the list of species 

 is the less accurate, since a far greater number of species than genera are 

 still undescribed. The extensive data given in these two volumes indicate 

 that the bulk of the ancestral land animals originated in the northern 

 hemisphere. It is worthy of note that the views expressed b} r Wallace and 

 some of the other earlier writers were far more conservative than those of 

 more recent date. 



It was during the interval from 1876 to 1890 that zoological, paleonto- 

 logical and geological data accumulated rapidly and yielded, especially, 

 the excellent summation of the geology of the face of the earth by Suess 

 and his views of the Gondwana Land (earlier suggested on purely paleon- 

 tological grounds by Xeumaver), and his considerations appear to have 

 paved the way for von Ihering's Archhelenis theory which has more or 

 less dominated most of the later studies on the zoogeography of South 

 America. 



Von Ihering has made, from time to time, slight changes in his theory, 

 in order to meet the demands of more recent investigations. In 1907, he 

 reconstructed the surface of the earth according to the views which he 

 obtained from a detailed study of the mollnsca. At the time, he main- 

 tained that, previous to and during a part of the Tertiary epoch, Brazil 

 (Archibrazil or Archamazonia) was connected by Archhelenis with Africa 

 and by Archiplata with Archinotis (Antarctic continent), which was also 



