Maksiiaij., Spkioiii', Cotton. — Yomtf/er Koch-Re ries of N.Z. 399 



thick, which may l)e traced for a considerable distance along the cliffs. This 

 band appears to be a very impure pumiceous earth. 



According to Hutton, the lowest beds seen in the section described 

 above are to be classed with the Papakuras, the upper beds with the Wai- 

 tematas. But the lower beds show a very close resemblance to the typical 

 Waitematas as seen near Howick, at the other side of the Turanga Creek, 

 and may be traced at intervals round the shores of Turanga Creek until 

 they are found to pass into the upper rocks which Hutton describes as 

 Waitematas, and which he says uncouformably overlie the greensands 

 (belonging also to the Papakura series) at Turanga Creek. On the other 

 hand, the uppermost beds seen in the cliffs between Motu Karaka and 

 Maraetai are quite distinct lithologically from the Waitematas as developed 

 elsewhere. 



Stratigraphically and lithologically, therefore, there seems no reason to 

 regard the lower beds between Motu Karaka and Maraetai as other than 

 Waitematas, and lithologically there is good reason to regard the upper 

 beds as distinct from the Waitematas, and younger. 



It may be of interest to note that at Slippery Creek, while the bed of 

 the creek is occupied by the fossiliferous limestone and conglomerate of 

 the Papakura series, the upper parts of the hills bordering the stream are 

 composed of alternating sandstones and clays showing a close resemblance 

 to the typical Waitemata beds. No evidence of unconformity between the 

 upper and lower beds just described could be found by the writer. 



Stratigraphical evidence too detailed to be given in this paper has been 

 collected by the writer which shows that there is little or no vertical differ- 

 ence between the lowest beds of the Waitematas and the lowest beds of 

 the Papakuras. 



In conclusion, therefore, it seems highly probable that the Waitemata 

 and Papakura series are part of one conformable series The differences 

 between the typical beds of the two series would, of course, be due to differ- 

 ences in conditions of deposition. 



IV. Deposition of Rocks of the Sertes. 

 (a.) General. 



A careful consideration of the stratification of these yomiger rocks, 

 a brief summary of which has been given in the preceding pages, has im- 

 pressed the writers with the belief that there is a single stratigraphical series 

 of younger rocks in New Zealand, and that this series is of very general 

 development and has a remarkably similar lithological succession in all 

 the localities. There are, however, some problems of considerable diffi- 

 culty that rec]uire solution if this statement be adopted. Briefly stated, 

 the main problem is of this nature. At the Waipara Gorge, Amuri Bluff, 

 and the Malvern Hills, fossils that have decidedly Cretaceous affinities are 

 found in the lowest rocks. Th« most important of these are Belemnites 

 australis Phillips, Conchothyra parasitica McCoy, Trigonia costata Hector, 

 Trigonia sulcata Hector, Inoceramus haasti Hochstetter, as well as a con- 

 siderable number of species of pythonomorphs and sauropterygians. In 

 the middle beds (Momit Brown) the Mollusca have a definitely Cainozoic 

 appearance, and 20 per cent, belong to Recent species. In the highest 

 beds 60 per cent. (Hutton) or 71 per cent. (Park) belong to Recent species. 

 Though it is not here intended to lay great emphasis on the percentage 



