422 Proceedings. 
Society by Mr. Crawford ; and in our last volume Capt. Hutton, in his paper 
on the alluvial deposits of the Waikato basin, also arrived at the conclusion 
that the sea has never occupied that large area of slightly elevated land, the 
most modern marine beds in it belonging to the upper miocene period. 
The mountains of New Zealand had, therefore, in all probability their 
greatest altitude during our great glacier period, but whether that period was 
attended by any marked changes in the climate analogous to the boreal con- 
ditions that prevailed during the equivalent period in the Northern Hemis- 
phere can only be determined by a critical comparison of the fossil shells from 
marine formations belonging to the same period, if any such can be found, 
Referring only to the South Island, and judging from the fossil plants that 
have been preserved in lignitiferous deposits belonging to the pliocene period, 
which even in the extreme south of Otago contain large masses of a resin 
allied to the kauri gum, I venture to anticipate that if there was any 
difference in the character of the climate at that time, it was not an extension 
of antarctic conditions, but the reverse. With regard to the period of greatest 
elevation, the interesting question arises whether New Zealand during that 
period continued to be isolated from other land areas, or whether its peculiar 
fauna and flora were established at a time still more remote. From the great 
depth of the ocean round the islands, and the wide expanse separating them 
from even the nearest islands—such as the Chatham and Norfolk Islands, 
both of which possess a closely allied flora—the physical changes required to 
produce the disseverance must have been enormous and have required a 
lengthened period for its accomplishment, 
We must suppose that the plains of barely consolidated tertiary strata 
that have been raised above the sea, and over which the progenitors of the 
Moas first reached New Zealand, have entirely disappeared by denudation 
and submergence, leaving the remnant of the race of giant birds to inhabit 
the limited area of these islands from that distant period down to the present 
time, 
If the hypothesis of an excess in the area of elevated land being the cause 
of the more powerful erosive action of the pleistocene glaciers is correct, since 
that time there must have been a steady diminution in the area of low-lying 
land and a gradual liberation of mountain slopes from their snow cap. The 
effect of this on the rapid diffusion of plant forms and the probable influence 
which it exercised on the production, by variation, of the species which now 
characterize our alpine flora, has been ably dealt with by your late President 
Mr. Travers, in the instructive series of lectures which he delivered two years 
ago to this Society. 
_ The description of the physical features of this very important epoch in 
New Zealand geology has been chiefly undertaken by Dr. Haast in various 
