318 Essays. 



and 'ForaminifercB, interspersed with perfect specimens of Terehratulce, 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 yan 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 

 Manuka,u 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- 

 cally described. 



It appears, however, that this district shows in places a flooring of 

 palaeozoic rocks, 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 

 B/odney to the Kaipara Harbour, on the ridge of which the escaped 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 secend-class harbours indent the northern peninsula. The 

 palaeozoic rocks of the "Barrier," on the left, contrast with the more tame 

 outline of the tertiary landscape on the right. 



* See Hochstetter, Fischer's Translatiou, p. 25. 



