BY E. M. JOHNSTON, F.L.S. 155 



this were in operation in France, Switzerland, and Great 

 Britain, where the Proteacece, formerlj' so abundant, have 

 now become extinct, 



Neogene Period. — Mr. Wilkinson is of opinion that 

 the great drift deposits left at different levels upon the 

 sides of the valleys as they were deepened towards the 

 close of the Neogene period indicate a much greater rain- 

 fall than at present, and this greater rainfall is inferred to 

 be due to the greater extent of glaciation of portions of the 

 northern and southern hemispheres. Whatever grounds 

 there may be for this view, it is clear, from the absence 

 of huge ice-borne erratics and other evidences on the 

 lower levels, we are not justified in assuming a very serious 

 and general refrigeration of the climate in the Australasian 

 region. 



That a considerable change of climate, however, had its 

 beginning at this time is most probable, as evidenced by 

 the sudden disappearance of the characteristic flora of the 

 older or Palceogene epoch ; and especially by the striking 

 contrast which its unstratified irregular drift deposits 

 (almost barren of all traces of life) present, as compared 

 with the more regularly stratified members, replete with 

 life remains, of the PalcBogene epoch. 



New Zealand. — In the preceding comparative table it 

 may be seen that the great physical changes in New 

 Zealand during the Tertiary period do not correspond with 

 those of Australia and Tasmania. Unlike the latter, the 

 several divisions in New Zealand are well marked by 

 successive marine formations, and these again are in most 

 cases easily distinguished by the different assemblages of 

 moUuscs contained in them, and by the striking differences 

 as regards the percentages which obtain in respect of 

 those of the species having living representatives. This 

 is at once apparent from the following abstract of the sub- 

 division as arranged by Professor Hutton : — 



Classification of Tertiary Formations in New Zealand. 



Contained Percentage of 

 Species still existing. 



Wanganui System (Pliocene) 70 to 90 



Pareora System (Miocene) 20 to 45 



Oamaru System (Oligocene) 9 to 10 



It is obvious, therefore, that with such marked charac- 



