Dkcembeb 7, 1900.] 



SCIENCE. 



861 



Puerco, although these localities are much 

 more distant from each other than North and 

 South America, correspond closely, but the 

 characters of the earliest Tertiary Pata- 

 gonian and North American mammalian 

 faunas are quite divergent. We find nothing 

 of the Toxodontia, Typotheriidse and true 

 Edentata in North America, and nothing 

 of the Artiodactyla, Perissodactyla, Ambly- 

 poda, etc., in Patagonia. The orders and 

 families which are represented in both 

 Patagonia and North America may be such 

 as were distributed over the whole area- 

 occupied by placental mammals in the 

 Laramie period. 



The third line of migration according to 

 Ameghino and Osborn was determined by 

 the land masses which connected Brazil 

 and Africa. In my papers, and especially 

 in the discussion with Ameghino, I have 

 insisted upon the value of this Eocene land 

 bridge, but I do not believe that it has 

 served for the distribution of mammals, as 

 I believe that Archamazonia was in the 

 greater part of the Tertiary separated by the 

 ocean from Archiplata. In this case Brazil 

 has received mammals only in the Plio- 

 cene time, when the communication with 

 Africa had long ago been interrupted. I 

 have examined the deductions of Ameghino 

 and Osborn with the purpose of verifying 

 the facts proving their opinions, but these 

 seem to be very insufficient. Osborn refers . 

 to the Pangolins and Aard Varks of the 

 Ethiopian region as introduced from South 

 America ' via Antarctica.' It must, how- 

 ever, be noted that these Edentata of the 

 old world occur also in Asia and that they 

 belong to the Nomarthra, while all the 

 Patagonian representatives are Xenarthra. 

 Both may be derived from a common 

 Australasian ancestor, but if the South 

 African Edentata had been derived from 

 the Patagonian Eocene fauna, they should 

 be Xenarthra. The genus Orycleropua 

 occurs also in the Miocene of Samos, and 



may have immigrated both to Samos and 

 to Africa from its Indo-australian home. 

 It may be observed here that I have 

 shown that the claw of the Dasypodidse 

 develops in the form of a hoof, and it is 

 wrong to classify the Xenarthra with 

 the Unguiculata, as they are Ungulata. 

 The Proboscidea and Hyracoidea are not 

 Patagonian mammals at all, although in 

 the Patagonian Laramie or Pyrotherium 

 fauna the Pyrotheriidse and Archseohyra- 

 cidae offer relations to the two above-men- 

 tioned living families. The case is the 

 same with the sole Patagonian Insectivore, 

 the genus Necrolestes, somewhat compar- 

 able with the Chrysochloridse of South 

 Africa. Evidently the few representatives 

 in the Patagonian Eocene of the Insec- 

 tivora, Prosimise and Hyracoidea are the 

 isolated mernbers of groups whicli were well 

 represented in other regions then in con- 

 nection with Patagonia. Thus the Chryso- 

 chloris argument for the Patagonian- South- 

 African migration is not better than the 

 hypothesis of a land-bridge uniting the 

 Antilles with Madagascar, the sole locali- 

 ties where representatives are found to-day 

 of the genus Centetes, which occurs also as 

 Wallace affirms in the European Tertiary. 

 The intimate relations between the fresh 

 water faunas of Africa and Brazil, and the 

 colossal difference which exists between the 

 fresh water faunas of Archamazonia and 

 Archiplata, prove that both territories dur- 

 ing the greater part of the Tertiary were 

 separated quite as completely as the two 

 Americas. In this case the mammalian 

 fauna of Patagonia may have reached Ecu- 

 ador or Colombia by means of the upheaval 

 of the Andes, but not Brazil, and both Brazil 

 and the ^Ethiopian region may have been 

 without mammals and especially placental 

 mammals, during the Eocene. When to- 

 ward the close of the Eocene this land- 

 bridge was submerged, there already ex- 

 isted many types that have been conserved 



