xlii INTRODUCTION. 



the larger continents, and which seems now to have disap- 

 peared from the face of the earth. 



The genus Mastodon forms an exception to that conti- 

 nental localization, not only of existing, but of pliocene 

 extinct genera of Mammalia above briefly dwelt upon. 

 The solitary character, however, of this exception serves 

 rather to establish the rule : at least, I know of no 

 other extinct genus of Mammal which was so cosmo- 

 politan as the Mastodon: it was represented by species, 

 for the most part very closely allied, if actually distinct, 

 in Europe, in Asia, in North and South America, and in 

 Australia : it is the only aboriginal genus of quadruped in 

 Australia which was represented by other species in other 

 parts of the world.* 



The most remarkable local existing Fauna, in regard 

 to terrestrial vertebrated animals, is that of the islands 

 of New Zealand, with which geologists have been made 

 familiar by Mr. LyelPs indication of its close analogy with 

 the state of animal life during the period of the Wealden 

 formation.-f- The only terrestrial Mammalian quadruped 

 hitherto discovered in New Zealand, whose recent intro- 

 duction into that island is at all doubtful, is a small Rat. 

 The unequivocally indigenous representatives of the warm- 

 blooded vertebrata are Birds, of which the Apteryx is the 

 most peculiar. It is the smallest known species of the 

 Struthious or wingless order, has the feeblest rudiments of 

 the anterior members, and not any of its bones are per- 

 meated by air-cells. This bird forms the most striking 

 and characteristic type of the proper or primitive Fauna of 

 New Zealand. 



* See ' Report on Australian Fossil Mammalia,' in the ' Transactions of the 

 British Association,' 1844, p. 239. 



f * Elements of Geology,' 8vo, 1838, p. 366, and ' Principles of Geology,' 1837, 

 vol. i. p. 204. 



