TERTIARY. 431 



dentition, the loss of nearly all the successional teeth, and the 

 modification of the limbs, the skeleton of these Australian mar- 

 supials does not appear to differ in any essential respects from 

 that of the Creodonta and Condylarthra met with in the 

 northern hemisphere at the dawn of the Eocene period. It is 

 quite likely, therefore, that they are the direct descendants 

 of some unknown families of the latter groups in the southern 

 hemisphere, which did not happen to pass into a higher grade 

 while their limbs and teeth were changing, like the allied types 

 of the northern hemisphere. Very large lizards (Megalania) 

 and tortoises (Miolania) are associated with the gigantic 

 extinct marsupials in the surface deposits of Queensland and 

 New South Wales; and there are also remains of the emeu 

 (Dfomanut), one of the two struthious birds which are still 

 characteristic of the Australian region. 



The Tertiary Fauna of New Zealand. 



New Zealand is still more isolated than Australia. So far 

 as known, it was never inhabited by any land-mammals until 

 they were introduced by man ; but, as in the case of Australia, 

 there is apparently no series of Tertiary deposits in this 

 country revealing its successive terrestrial faunas. Quite 

 recently it was the home of the struthious birds of the family 

 Dinornithida? the moas of the Maori natives ; and these birds 

 attained a development such as has never been equalled by 

 struthious birds elsewhere. They were also associated with 

 large rails, which are now extinct. The diininutive apteryx 

 and weka-rail are the sole survivors at the present day. 

 Among lizards the existing tuatera (Sphenodon or Hatteria) is 

 noteworthy as being the sole survivor of the order Rhyncho- 

 cephalia, which had numerous representatives and was very 

 widely distributed on the globe during the early part of the 

 Secondary era. 



