PURNELL. — On the Wanganui Tertiaries. 457 



of tint could be drawn, although were the human vision sufficiently acute the 

 lines where each tint attains it maximum, and which give the tone to the 

 whole sky, could doubtless be discerned. 



I have collected from the Landguard Bluff a large assortment of shells, 

 including Fecfen jacohceus, Tellina (large and small species), Cardita, Eotella 

 zealandicus, Myadora, a small and very fragile Venus (which I think is not 

 catalogued), Nucula^ Fusus (two species), Turritella, a small Scalaria, Ostrem, 

 Lucina, Natica, CrepidulcB, a large Valuta, Rissoa, Venericardia, and Donax, 

 all, it will be observed, betokening a climate similar to the present. I refrain 

 from attempting to give specific names, for the reason that I have not proper 

 materials at command to determine them^ and nothing has tended more to 

 complicate the intensely perplexing nomenclature of shells than the hasty 

 efforts of collectors to attach names to specimens which are not quite familiar 

 to them. 



Considering the abundance of cephalopods in the New Zealand waters of 

 the present day, it is surprising that I have been unable to discover a single 

 fossil of a cephalopod in the district, nor is one marked in the Museum 

 catalogue. What does this indicate ? The fossils collected show the climate 

 to have been suitable for cephalopods, which, however, have a wide range, and 

 some are very hardy. 



From this sketch it would appear that the oldest fossiliferous stratum 

 within a radius of four or five miles from the town of Wanganui is the tuff in 

 the cliffs mentioned on the east bank of the river ; the next oldest, the blue 

 clay of Shakespeare Cliff; and the youngest, the beds overlying the blue clay 

 and those at the Landguard Bluff — the strata thus growing older as they 

 ascend the river. To ascertain the comparative ages of these formations would 

 require the fossils of each to be examined separately, with the view of 

 determining the proportions of extinct to recent shells. Captain Hutton, in 

 his Catalogue, has lumped the three formations together, and thus makes them 

 out to contain seventy-six per cent, of recent shells, which would make the 

 beds of about the same age as the Sicilian volcanic tuffs (newer pliocene). It 

 will probably be found that the lower beds are of the same age as these tuffs, 

 perhaps a little older, but there is such a marked difference, palseontologically 

 speaking, between the tuff bed on the left bank of the Wanganui river and 

 the upper beds of Shakespeare Cliff, which are of very recent origin, that their 

 fossils ought not to be mingled together in order to strike an average. 



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