sheets of trachytic and basaltic lavas, ashes, and
agglomerates; lava-floods descending from the ruptured craters of ashes
and scoriae; old crater-basins converted into lakes; geysers, hot springs
and fumaroles which may be counted by hundreds, and cataracts breaking
over barriers of siliceous sinter; and, lastly, lofty volcanic mountains
vying in magnitude with Vesuvius and Etna. All these wonderful
exhibitions of moribund volcanic action seem to be concentrated in the
northern island of Auckland. The southern island, which is the larger,
also has its natural attractions, but they are of a different kind;
chief of all is the grand range of mountains called, not
inappropriately, the "Southern Alps," vying with its European
representative in the loftiness of its peaks and the splendour of its
snowfields and glaciers, but formed of more ancient and solid rocks than
those of the northern island.

(_a._) _Auckland District._--We are indebted to several naturalists for
our knowledge of the volcanic regions of New Zealand, but chiefly to
Ferdinand von Hochstetter, whose beautiful maps and graphic descriptions
leave nothing to be desired.[1] In this work Hochstetter was assisted by
Julius Haast and Sir J. Hector. From their account we learn that the
Isthmus of Auckland is one of the most remarkable volcanic districts in
the world. It is characterised by a large number of extinct
cinder-cones, in a greater or less perfect state of preservation, and
giving origin to lava-streams which have poured down the sides of the
hills on to the plains. Besides these are others formed of stratified
tuff, with interior craters, surrounding in mural cliffs eruptive cones
of scoriae, ashes, and lapilli; these cones are scattered over the
isthmus and shores of Waitemata and Manukau. The tuff cones and craters
rise from a floor of Tertiary sandstone and shale, the horizontal strata
of which are laid open in the precipitous bluffs of Waitemata and
Manukau harbours; they sometimes contain fossil shells of the genera
_Pecten_, _Nucula_, _Cardium_, _Turbo_, and _Neritae_. As the volcanic
tuff-beds are intermingled with the Upper Tertiary strata, it is
inferred that the first outbursts of volcanic forces occurred when the
region was still beneath the waters of the ocean. Cross-sections show
that the different layers slope both outwards (parallel to the sides)
and inwards towards the bottom of the craters. Sometimes these craters
have been converted i