808 Transactions. — Geology. 
In June 1875, Mr. S. H. Cox, in his report on the Raglan and Waikato 
distriets, * said that the sandstones and clays of Mercer were probably the 
equivalents of the Waitemata series, and he considered them to form part 
of Dr. Heetor's cretaceo-tertiary formation, now called the ** Waipara 
System ;” at the same time saying that **the fossils do not absolutely fix 
them as such." This is certainly very true, for the only fossil in his list 
of any chronological value is Dentalium manum, Hutton, which is found in 
the pliocene beds at Wanganui and Petane. In his further report, however, 
Mr Cox says that * they are in this locality the higher member of the Leda 
marls."i In 1879 Mr. Cox was sent to examine the country from Auckland 
northwards; tracing the Waitemata series towards the Kaipara and Cape 
Rodney, he found that it gradually changed into greensands mixed with 
much voleanie ash, and that at Mahurangi and at Komiti Point, in the 
Kaipara District, it rested unconformably on **chalk-marls and hydraulic 
limestones,” thought to be of cretaceo-tertiary age. This, together with the 
fossils found at Komiti in the Waitemata series, led him to alter his former 
opinion, and to consider the Orakei Bay Beds as lower miocene.t Dr. 
Hector in his Progress Report for the same year demurs to this conclusion 
and suggests that the Waitemata series ought to be divided at the horizon 
of a voleanic ash bed in the cliffs under Parnell, which he calls the ** Parnell 
Grit;” all below this bed, including the strata at Orakei Bay, being still 
retained as cretaceo-tertiary : his reason being that Pecten zittelli, Hutton, § 
and many other Orakei Bay fossils are found at Komiti Point only in sandy 
marls and grits which underlie tufaceous beds containing a number of 
lower miocene forms.| Mr. Cox, however, who collected the fossils, says 
distinctly in his report that “these beds [i.e., the marly grits] curiously 
enough contain, associated with a great preponderance of lower miocene forms, 
the Pecten zittelli, Hutton, and P. Jischeri, Zittel, of Orakei Bay, on the 
occurrence of which we have ascribed a cretaceo- -tertiary age to these beds,” 1 
and he does not mention any fossils in tufaceous beds. 
In the following year Mr. Cox was sent to re-examine this point, but he 
reported that he was more than ever convinced of the correctness of his last 
year’s work, although he thought it possible that the Waitemata series 
might be of eocene age.** He examined the cliffs from Auckland to Orakei 
* Reports of Geological Explorations, 1874-76, p. 9. 
t Reports of Geological Explorations, 1876-77, p. 22. 
1 Reports of Geological Explorations, 1879-80, p. 37. 
§ Dr. Hector and Mr. Cox often call this shell Pecten pleuronectes; it seems therefore 
necessary to point out that P. pleuronectes, L., is a living species which has never been 
found in New — 
{| 4. xii. {I Le., p. 17. On page 33 he gives a list of these fossils. 
si fiti influenced by "i mistake of supposing that nummulites occur at Orakei 
Bay. (Reports 1879-80, p. 25.) 
