EXPLANATION OE THE MAPS. 
64 
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O 
liuiiga are numerous country seats, villas, and farms. Alon 
the road, villages are rapidly forming, such as Newmarket, 
Mount St. John, and Epsom. t Every sign of the former 
wildness of the isthmus has vanished. The old New Zealand 
vegetation has given Avay to European plants. Scoria walls 
and green hawthorn hedges divide the various estates; green 
meadows, gardens, and fields charm the eye. Everywhere 
herds of fine cattle are seen grazing in the fields. Omnibuses 
are constantly passing on the roads, and the whole forms a 
picture of a fresh and happy life. 
The isthmus of Auckland is also one of the most interesting 
volcanic districts of the globe. It owes its distinguishing 
feature to a great number of extinct volcanos, with more or 
less distinctly preserved craters and lava streams which form 
extensive scoria fields at the foot of the hills, or with tuff- 
craters which encircle the scoria cones like an artificial wall, 
and are irregularly distributed over the isthmus and the 
neighbouring banks of the Waitemata and Manukau. The 
volcanic activity at each new eruption seems to have taken a 
different course from the former, and divided itself into 
numerous small cones. My map of the isthmus, which 
extends over a district of 20 miles in length, by 12 in width, 
shows not less than 63 independent points of eruption. 
These are volcanos on the smallest scale, forming cones of 
an elevation of from 300 to 600 feet above the level of the 
sea. The highest amongst them is Rangitoto, which rises at 
the entrance of the harbour of Auckland to the height of 900 
feet. But they are perfect models of volcanic cones and 
crater formation, and offer a large field of geognostic 
observation, refuting entirely the theory of elevation craters 
by Leopold von BuchA 
These mountains rise on a base consisting of tertiary sand¬ 
stone and argillaceous marl, the horizontal and only locally 
disturbed strata of which are easily recognisable on the steep 
banks of the "Waitemata and Manukau Harbours. The 
examination of these isolated points of eruption gives proof 
A description in detail will he given in tlie scientific publication of 
the “Novara” expedition, and will appear in the volume which embraces 
the geology of New Zealand, 
