PACIFIC CONTINENT 
427 
New Zealand with Chile, which, as he maintains, ceased to 
exist at the close of the Eocene Period. 
Certain geological features no doubt point to a former west¬ 
ward extension of Chile. L>r. Burckhardt * showed that in 
western Chile there are enormously thick deposits of porphy- 
ritic conglomerates which become more attenuated and com¬ 
posed of lighter sandy material as we proceed eastward. 
Hence he argues that these deposits were laid down on an 
ancient shore-line of a vast western land-mass of which the 
existing coast cordillera of Chile is the last remnant. He 
advocates, in fact, nothing short of what we might call a 
Pacific Continent which lay mainly to the westward of Chile. 
That land formerly extended in that direction I have en¬ 
deavoured to demonstrate from purely faunistic evidence, but 
I believe that it was part of a great circum-Pacific belt of 
land which stretched mainly northward, communicating from 
time to time with Central America and the Antilles, and also 
with Mexico and western California, and then eventually bend¬ 
ing across to eastern Asia in a great loop and thus joining 
New Guinea, Australia and New Zealand. That Central 
America and western North America must have been thus 
connected by land with the Australian region has been urged 
above on several occasions when dealing with the North 
American fauna. It might be argued that if such a northern 
land connection once existed, uniting Chile with the Austra¬ 
lian region, there would no longer be any necessity for postu¬ 
lating an antarctic land bridge. Professor L)ahl has recently 
taken up this attitude, illustrating his adverse criticism against 
the antarctic theory by means of the distribution of spiders. 
He does not adopt, of course, my view of a northern semi¬ 
circular land belt because this theory has never before been 
published and is entirely my own. His contention is that the 
continents and oceans have remained within the lifetime of 
the present fauna what they are now, that is to say, within 
the more recent geological periods, except that the great land- 
masses were joined in the north. A powerful centre of dispersal 
existed in the arctic regions, according to Professor Bahl.f 
* Burckhardt, C., “ Traces d’un ancien continent,” pp. 1S6 — 190. 
t -Dahl, F., “ L>ie Verbreitung der Spinnen.” 
