318 Essays. 
. and Foraminifere, interspersed with perfect specimens of Terebratule, oysters, 
Pectens, and other shells.* 
The aspect of the west coast from Taranaki, we may say as far as the 
Kaipara Heads, or even to Cape Maria van Diemen, is hilly and broken, 
The rocks principally consist of marine tertiaries, viz. sandstones and 
limestones alternating with doleritic and trachytic lavas, conglomerates! 
and breccias of the same, an occasional volcanic cone (as at Karioi to the 
southward of Whaingaroa Harbour), considerable formations of drift sand 
forming dunes which reach a height of 500 feet above the sea, and patches 
of secondary rocks at the heads of the Kawhia and Whaingaroa harbours. 
The coast ranges are hardly high enough to be called mountainous, but 
almost too high to be described as hilly. 
The sand dunes appear to a great extent between the Waikato and 
Manukau Heads, and also at some points to the northward of the latter, but 
the country north of Auckland has never, to my knowledge, been systemati- 
eally described. 
It appears, however, that this district shows in places a flooring of 
palæozoic tocks, and.a large proportion of marine tertiaries. Secondary. 
rocks are said to occur in the harbour of Hokianga to a limited extent. 
Limestones and calcareous sandstones are found profusely distributed in 
the Kaipara Harbour, of which the age is undetermined, but they are 
probably tertiary. Coal, of which the beds appear to be of considerable 
thickness, is found to the northward, and at the Bay of Islands appears to 
be of good quality, whatever its geological age may be. ` 
The northern peninsula is dotted over with numerous volcanic cones, 
and other remains of igneous action. The range which runs from Cape 
Rodney to the Kaipara Harbour, on the ridge of which the eseaped Waikato 
prisoners have built their * pa," seems to be mostly composed: of tufaceous 
materials, frequently arranged in spheroidal concretions. Similar rocks are 
found at Matakana and near Mahurangi, not far from which (at Waiwera) 
are hot springs. 
At Wangarei North Head are the remains of a magnificent crater, which 
formerly may have included the “Hen and Chickens” group of islands, 
either as one gigantic crater or as a series of cones forming a volcanic chain. 
Almost all of the old crater wall is now broken down and has disappeared, 
but part of it, I think, may still be made out from inland of the heads. 
Many first and second-class harbours indent the northern peninsula. The 
palwozoic rocks of the “Barrier,” on the left, contrast with the more tame 
outline of the tertiary landscape on the right. 
* See Hochstetter, Fischer’s Translation, p. 25. 
