HuTTON.— 0/i tlie Moas of Netv Zealand. 145 



well as other fossils, including at least three living species of 

 Mollusca,- and, if this fragment is part of a moa-bone, it is 

 the oldest at present known. Doubts have been expressed as 

 to the ornithic nature of this fragment, and it has been sucr- 

 gested that it may be reptilian. Mr. H. O. Forbes has eve^'n 

 gone so far as to say that, " as reptihan bones have since been 

 obtained from the same horizon, it was probably of this 

 nature."! But no second examination of the fragment has 

 been made, and it is not probable that the English authorities 

 mistook reptihan for bird bones. Also no other reptilian bones 

 have been found m these septaria, nor are reptilian bones known 

 to occur m any other part of New Zealand associated with the 

 species of shells found at Hampden in the beds containing the 

 septaria : consequently, whatever age these beds mav be'' Mr 

 Forbes cannot be correct in saying that reptilian bones have 

 been found on the same horizon ; for geological horizons are 

 determined by a similarity of fossils. Omitting this frag- 

 ment as uncertain, we have undoubted traces of the moas in 

 New Zealand m early Pliocene, or perhaps in Upper Miocene 

 times. ■■■ i-j. , 



Now comes the question, How came the moas to be in 

 New Zealand? Mr. A. E. Wallace supposes that the moas 

 are descended from Eatite ancestors of the Northern Hemi- 

 sphere and have spread southwards through New Guinea into 

 Australia and New Zealand. If this be so the migration into 

 N ew^ Zealand must have taken place a very long time a^o In 

 the Miocene and Oligocene periods New Zealand was of much 

 smaller dimensions than at present; but in the Eocene, and 

 again probably, m the older Pliocene, it was much larger, and 

 stretched m a north-west direction towards New Guinea 

 But, as I have pointed out in former addresses to this In- 

 stitute, biological evidence assures us that New Zealand has 

 never been jomed to Australia or to New Guinea since the 

 Cretaceous period, a time when there were no struthious birds 

 m existence ; and it is difficult to explain how these birds if 

 they migrated from the Northern Hemisphere, entered Aus- 

 tralia and New Zealand without being accompanied by 

 placental mammals. Mr. Wallace supposes that they either 

 flew or swam across a strait which was impassable to the 

 mammalia. § That they flew across is, on this hypothesis, 

 impossible, because the special characters of the Eatitse are 



" Trans. N.Z. Inst., vol. xix., p. 426. 



t Trans. N.Z. Inst., vol. xxiii., p. 372 

 „ Jr ^^n-/^<i Mag. Nat. Hist., ser. 4, vol. xiii., p. 25 ; ser. 5, vol xiii 

 p^42o; and vol. xv., p. 77. N.Z. Journal of Science, 1884-85, pp 1 and 



§ " Island Life," p. 450. See also Owen, Ext. Birds of N.Z p 136 ■ 

 10 



