888 Transactions. — Geology. 



correlation of the Mount Potts fossils with the marine strata underlying the 

 coal measures of New South Wales is incorrect, and that the proper 

 equivalent of the latter in New Zealand is to be found at the base of the 

 Maitai series. For instance, in addition to the presence of saurian bones > 

 there is a total absence of true Spirifers ; the broad- winged Spirifer that 

 has been so often mentioned in connection with the Mount Potts beds being 

 really a Spiriferina of the sub-genus Trigonotreta, King, distinguished by 

 having a strong central septum in the rostral valve and a punctate shell 

 structure, characters wholly wanting in true Spirifers. This particular 

 fossil is indeed identical with a species very characteristic of the Permian, 

 and it has been collected in many other parts of New Zealand where the 

 stratigraphy leaves no doubt of its true position in that formation. No 

 true Spirifer has yet been found on the eastern side of the New Zealand 

 Alps, and no Spiriferina of the type of Trigonotreta is found in the 

 true Spirifer beds at Eeefton and in New South Wales, which I refer to 

 Lower Carboniferous or Devonian. The ample collections from both the 

 Australian and New Zealand localities in support of this are in the Colonial 

 Museum, and here therefore arises a conflict of evidence that can only be 

 cleared up by knowing what fossils were really submitted to Professor 

 McCoy, and what was the wording of his report on them. 



Dr. von Haast, however, could not accept on Professor McCoy's alleged 

 authority that the Clent Hills plant beds were Jurassic, because he was "con- 

 vinced that they were of the same age" as the Mount Potts beds. He con- 

 siders this divergence from his authority has been since justified, because he 

 thinks Professor McCoy has been worsted in a controversy about the age of 

 the plant beds associated with coals and marine fossils in New South Wales. 

 But in this particular case of the Clent Hills the experience in New Zealand 

 has proved that Professor McCoy was quite correct in his alleged determi- 

 nation, and this without a whit affecting the question of the age of the 

 New South Wales plant beds, as there is not a single fossil plant found in 

 the proper coal formation of New South Wales which also occurs among 

 the fossil plants of the Clent Hills beds ; on the other hand the latter agree 

 perfectly with fossil plants found in the Clarence Eiver (New South Wales), 

 in Queensland, and in Tasmania, which are always accepted as Jurassic. 

 We thus find that the Mount Potts and the Clent Hills beds form almost 

 the lowest and the highest numbers of a great Permio-jurassic system, the 

 sequence of which has been very clearly worked out in other parts of New 

 Zealand, where there had been less of the " folding and crumpling " to which 

 Dr. von Haast alludes. The Permian base of this system has never been 

 found resting with any approach to conformity on the Maitai series, which is 

 Lower Carboniferous, the Upper Carboniferous formation or the Lower Coal 



