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 “ Arclihelenis.” Archi¬ 
plata is still joined at this time to Australia by means of the 
antarctic continent “ Archinotis,” while Archiguiana 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 
fiir MineraJogie und Geologic,” 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. 
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