306 Transactions. 



system, of older Pliocene age. Such. " zoual " fossils are obviously of no 

 importance, for the other species is at the present time represented by a 

 f;ingle specimen only. 



Of Park's list of twenty-three Waihao species, as many as sixteen sj)ecies 

 occur in the lists that we have given. In the middle division of his Miocene 

 there are twenty-four species of Mollusca given as most distinctive : thir- 

 teen of these are given in our lists. Finally, twenty-nine are given as most 

 abundant in the upper division of his Miocene, and some twenty-three of 

 these were recognized by us. This list of twenty-nine represents in all 

 but two the species that he found at Awamoa, so the percentage of them 

 that would be expected to be found in our lists would necessarily be high. 



It appears, then, that the horizon from which we have collected — viz., 

 that immediately above the Hutchinson's Quarry -greensands — corresponds 

 palaeontologically almost equally with any of his three Miocene horizons. 

 Finally, Park gives a list of ten species which he says never occur above 

 the Ototara-Waitaki stone. Of these, all except one species are in our lists. 

 In each of our localities the beds lie above the limestone, of which we believe 

 that there is but one horizon. At the Devil's Bridge the fossil horizon 

 obviously rests above the limestone, in that locality called by Park the Wai- 

 taki or Upper limestone: The same position cannot be questioned for the 

 Ardgowan beds, and in our opinion the beds at Awamoa, Pukeuri, and 

 Target Gully obviously have the same position. 



The actual age of these beds is very difficult to state. Until Mr. Suter's 

 revision of the Mollusca appears we are not able to say how many of the 

 species are Recent, but we are able to assert, that it is not less than 40 per 

 cent., and that it may be as much as 50 per cent. Our lists include seven 

 species — Trochus tiaratus, Amfullina undulata, Phalium achatimim pyrum, 

 Mt rex octogonus, Trophon plebeius, Trophon paivae, and Tellina glabrella — 

 which have never been found below Pliocene rocks previously, and six of 

 tliese species are Recent. Tbere are some eight new species that we hope 

 that Mr. Suter will describe in the future. One genus — Cypraea — has 

 not previously been known to have representatives in New Zealand, though 

 Mr. Suter now states in MSS. that Hutton's Volvaria ficoides should be 

 placed in that genus. 



A comparison between these beds and those of the Mount Brown horizon 

 of the Lower Waipara described by Speight* is interesting. In the Waipara 

 l^eds Mactra, Glycimeris, and Natica are extremely common, but Limopsis 

 is absent and Cucullaea is most unusual. However, in this locality the 

 most fossiliferous beds appear to be about 1,000 ft. above the limestone, 

 and therefore the fossils in all probability represent a higher horizon than 

 the one from which we have collected. 



Bibliography. 



[The abbreviations used are : T.N.Z.I., Transactions of the New Zealand Institute ; 

 Rep. G.S., Reports of the Geological Survey of New Zealand ; Q.J.G.S., Quarterly 

 Journal of the Geological Society.] 



1850. Mantell, G. A. "On the Geology of New Zealand." Q.J.G.S., 



vol. 6, p. 324. 

 18(39. Train; C. " Tertiary Series of Oamaru and Moeraki." T.N.Z.I., 



V!)!. 2, p. 166. 



* Trans. N.Z. Inst., vol. 44, p. 221. 



