THE ORIGIN OF THE FAUNA AND FLORA OF NEW ZEALAND. 263 
Let us now see what paleontological evidence there is to fix 
the date of this upheaval. Marine strata belonging to the 
Pareora System, and containing, so far as we know at present, 
from 20 to 45 per cent. of living species of mollusca, are found 
throughout New Zealand from Southland to Auckland. These 
may be considered as of miocene age. The next series, in 
ascending order, shews a very different assemblage of fossils. It 
is called the Wanganui System, and is widely spread over the 
North Island. The marine beds contain a number of shells, of 
which from 70 to 90 per cent. are still living. This system must 
therefore be referred to the newer pliocene. No fossiliferous 
marine rocks of this system are known as yet in the South 
Island, but it is represented by thick masses of unfossiliferous 
gravels. Marine deposits with shells of still living species, and 
therefore of pleistocene age, are found at various places in both 
islands, from Auckland to Oamaru and Dunedin,* and in addition 
there are many unfossiliferous shore deposits and other indica- 
tions that a gradual elevation was going on during the whole 
of the pleistocene period all round the coasts south of Auckland. 
While therefore we have ample evidence in fossiliferous rocks 
that the land stood ata lower level than at present during the 
miocene, newer pliocene, and pleistocene periods, there is a break 
in our geological record in the older pliocene of which we have 
no trace in marine strata. This can only be accounted for by 
one of two suppositions ; either (1) that all the beds of that age 
have been covered up; or have been removed by denudation ; 
or (2) that during this period New Zealand stood at a higher 
level than at present, in which case the marine beds would be 
deposited at a level which is now below the sea, and consequently 
inaccessible to us. As we have both miocene and newer pliocene 
beds in abundance, there is no reason for thinking that the first 
supposition is correct ; while we have good réasons, in the dis- 
tribution of our fauna and in our old glacier marks, for believing 
that New Zealand was considerably elevated in the pliocene 
period. The conclusion therefore is that our last great glacier 
epoch was caused by an elevation of the land that took place 
during the older pliocene ; or, more precisely, in the interval be- 
tween the Pareora and the marine beds of the Wanganui 
systems. Possibly this elevation may have continued in the 
South Island during the whole of the pliocene, but it was cer- 
tainly over before the advent of the pleistocene. In my address 
last year I mentioned this elevation as necessary to explain the 
flora of the Kermadec Islands, but I had to postpone the proofs 
of it until now. 
It appears therefore that, so far as New Zealand is concerned, 
Mr. Wallace is incorrect in his statement already quoted, that 
the traces of ancient glaciers “point to a period so recent that it 
*See Trans. N.Z. Inst., V., p.. 387; Geology of Otago, pp. 70 and 78; 
M‘Kay, Geol. Reports 1878-9, p. 84; Von Haast, Geology of Canterbury, p. 366; 
Percy Smith, Trans, N.Z. Inst., XIII., p. 398. 
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