374 Transactions. — Geology. 



between the Petane sands and the overlying shelly limestones, 

 thus admitting of the reduction by denudation of the intervening 

 beds down to the meagre thickness which they now present. 



"What may be the final conclusions respecting this stratigra- 

 phical difficulty I am not prepared to hazard an opinion. Mean- 

 while, I do not consider the upper miocene Te Aute limestone 

 present in Scinde Island. The palasontological evidence brought 

 forward by Captain Hutton is against this, and the evidence, as 

 collections are added to, is likely to be strengthened rather than 

 weakened ; that is, if the Pohui limestone be the same as the 

 lower limestone in Scinde Island, which it is asserted to be. 



One difficulty in the way of regarding these rocks as of 

 pliocene age has been the number and remarkable size of the 

 extinct forms of Pecten found in them, which are not supposed 

 to occur in the upper shelly limestones of admittedly pliocene 

 age, and which occur also abundantly in the Te Aute limestone. 

 This is by no means an insuperable difficulty, and we have only 

 to consider them as exceptional, and in reality belonging to 

 an older period. Looked at in that light, they would have to be 

 excluded in arriving at the age of the beds, as determined by the 

 percentage of living species ; and were this done, all doubt of the 

 pliocene age of the beds would be removed. There would then 

 be 71 per cent, of recent species found in the beds. Were these 

 Pectens retained, and the five recent species found at Pohui 

 added to the 15 occurring in Scinde Island, we should have a 

 like result — viz., nearly 70 per cent, of recent species from the 

 limestones of this horizon. 



From the Lower Wairarapa Valley, N.E., to the northern part 

 of Hawke's Bay Provincial District, the Te Aute limestones 

 everywhere close the middle tertiary sequence, as seen in this 

 part of the North Island. The Pareora formation of Hutton, 

 characterised by a proportion of recent species equal to 37 per 

 cent., should, one would think, underlie the Te Aute limestones, 

 at least ought to underlie its supposed representative in Scinde 

 Island, with 61 or 70 per cent, of its species recent. And yet, 

 if we accept Captain Hutton's latest classification, we are 

 required to suppose that the Pareora beds, containing little more 

 than half the number of living species, are actually the older 

 series. The Te Aute limestone cannot be made to occupy this 

 position relative to the Pareora series, without setting aside all 

 the evidence obtainable, both palasontological and stratigraphical ; 

 but if regarded as the highest member of that series, this would be 

 more in accord with what is known as to its actual position. It 

 may be the lowest member of the young tertiary sequence ; more 

 probably, along the East Coast of the North Island it closes the 

 middle tertiary series. 



