100 Capt. F. W. Hutton on the Geographical 



been three principal upheavals in New Zealand, in the Lower 

 Cretaceous, Lower Eocene, and Older Pliocene periods respec- 

 tively, and that these were divided Lj two insular jjeriods, 

 viz. during the Upper Secondary (Danian) and from the com- 

 mencement of the Upper Eocene to the close of the Miocene, 

 thus agreeing completely with the zoological evidence. 



The dates assigned by the geological evidence also agree 

 well with those derived from zoology. We have seen that it 

 is necessary to suppose that the first great antarctic continental 

 period w' as anterior to the date of the spread of the mammals 

 southwards. Now a few marsupials are known in the Triassic 

 period ; but it is quite possible either that they spread very 

 slowly, or that barriers existed that prevented any southward 

 migration. In the Eocene period, however, some placental 

 mammals were in existence, although marsupials (not of Aus- 

 tralian types however) still formed in Europe the principal 

 mammalian life ; and if the supposed barriers to a southward 

 migration were still in existence, we know, from what hap- 

 pened in the northern hemisphere, that the whole, or nearly 

 the whole, of the marsupials w^ould be exterminated. The 

 marsupials, therefore, must have migrated south not later 

 than the Eocene period ; and as we know that our connexion 

 with Australia and South America must have been before that 

 migration, it follows that the first, or Lower Cretaceous, period 

 of upheaval must have been the time of the antarctic continent. 

 This is rendered still more probable by the fact that our 

 Jurassic fossils show a connexion with Australia only, while 

 our Upper Secondary fossils show for the first time a relation 

 to South America. The fact, too, of the Cretaceo-Oolitic 

 rocks of Tierra del Fuego having been largely disturbed, 

 metamorphosed, and broken through by dykes of greenstone, 

 shows that extensive elevatory movements have taken place 

 there also since they were deposited. It is therefore to the 

 Lower Cretaceous period that Ave must probably look for the 

 time of the dispersion of the Struthious birds. With regard 

 to the date of the second or Polynesian continental period, the 

 only zoological evidence we have is that it probably preceded 

 the wide dispersion of the Hemiptera and the butterfly section 

 of the Lepidoptera. This, therefore, could not have been later 

 than the Eocene ; for a fossil butterfly ( Vanessa pluto) has 

 been found in the Lower Miocene deposits of Radaboj in 

 Croatia, and fossil Heteroptera in the Miocene beds of CEningen 

 in Switzerland. The elevation during the Lower Eocene 

 period was therefore probably the one which formed the con- 

 tinent that I have described as including New Caledonia -and 

 some of the Pacific islands. At this period probably Northern 



