FAUNISTIC ELEMENTS 339 



the latter the remainder of South America, the two parts 

 being separated by a broad ocean except for a narrow western 

 land bridge. Each of these great islands had its own peculiar 

 fauna and flora, but Archiguiana must have been connected 

 by land with Africa until Oligocene times, and Archiplata 

 with New Zealand and Australia during the Mesozoic 

 Era. 



With the gradually increasing knowledge of palaeontology 

 Dr. von Ihering's original ideas naturally became subject to 

 various modifications. Thus in a map representing the con- 

 ditions of land and water during the Eocene Period, and pub- 

 lished in 1907 (Fig. 17), not Archiguiana but Archiplata is 

 connected by land with Africa and also India, the whole of 

 this ancient continent being called " Archhelenis." Archi- 

 plata is still joined at this time to Australia by means of the 

 antarctic continent " Archinotis," while Arehiguiana is 

 united with the West Indies and parts of Central America 

 into a large land-mass which stretched forth, westward to the 

 Sandwich islands, and was called " Pacila." Quite recently 

 the same author brought forward testimony in favour of a 

 Miocene land bridge between Central America and eastern 

 Asia. I have already alluded to it in the previous chapter. 

 Dr. von Ihering now tells me that he will shortly publish 

 a revised palaeogeographical map in the " Neues Jahrbuch 

 fur Mineralogie und Geologie," in which these features are 

 indicated. 



The same problem, studied from the point of view of the 

 distribution of fresh-water crabs and crayfishes, led Dr. 

 Ortmann* to somewhat different conclusions. At the end 

 of the Mesozoic Era he recognises the existence of the island 

 of Brazil, which had previously been connected with Africa, 

 while Guiana was still joined to western North America on the 

 one hand and Africa on the other. The independent Chilean 

 tract of land was connected with Australia by means of the 

 supposed antarctic continent (Fig. 15). At the commence- 

 ment of the Tertiary Era South America had assumed its 

 present shape, except for an elongated bay extending inland 

 from the Atlantic Ocean into the valley of the Amazon. In 



* Ortmann, A. E., "Distribution of Decapods," pp. 379 381. 



z2 



