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 

 deviation, 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 jDhysical 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 })lant forms and the probable influence 

 which it exercised on the production, by variation, of the sj^ecies 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 b}'' Dr. Haast in various 



