308 Essays. » 
width of about four miles, and form a succession of gigantic “ hog-backs,” 
rising from Cook Strait to an extreme elevation of ‘over 5,000 feet nearly 
opposite the Horowhenua river and lake. At this latter place they attain 
the greatest width, and afterwards sink to an altitude of 1,300 or 1,400 feet, 
and at the gorge of the Manawatu their breadth is decreased to four or five 
miles. Here the striking feature is observed of a river (the Manawatu) 
rising on the eastern side of the main range, passing through a narrow 
gorge, and falling into the sea on the western side of the island. This 
phenomenon also occurs in the opposite direction, viz. from west to east, 
with various Hawke Bay rivers. , The mountains which may be regarded as 
the southernmost group of the main range, pass under the general names 
of Tararua and Rimutaka, but have various spurs and offshoots bearing 
subordinate denominations. 
From the northern side of the Manawatu Gorge, the main range, which 
is composed of rocks of a similar geological character, continues its course 
to the N.N.E., under the name of Ruahine, attaining an elevation of 5,000 
or 6,000 feet, and, like the above described more southern group, drops again 
to the northward, to be succeeded by the Kaweka range, and that again by 
other ranges continuing the line to Hicks Bay, westward of the East Cape. 
These ranges in the latter part of their course have never been surveyed 
nor even examined, but their general character has been roughly determined 
by observation in passing along the coast. 
Parallel ranges of paleozoic rocks are found both east and west of this 
line, but none of them, like the above described mountains, traverse the ' 
island from end to end. 
The rocks of these ranges consist of sandstones of different kinds, vary- 
ing from a soft decomposing texture and yellow colour, to a hard compact 
blue and grey semi-crystalline rock, plant beds, tentaculite beds, slates, 
(some being pyritous), diorite schist, jasperoid rocks, and a little serpentine. 
ore modern eruptive rocks also appear to penetrate the ranges, as seen 
at Mukamuka and elsewhere, consisting of amygdaloidal trap and basalt. 
The line of strike of these eruptive rocks will probably be found to be 
shown. by the jasperoid rocks, supposing these to have been metamorphosed 
into their present state by the effect of the intrusive dykes, 
The fossils that have been found in the palæozoic ranges are few and 
indistinct, and, as far as we know, are confined to those discovered by myself 
in the neighbourhood of Wellington. One from Belmont Hill, above the 
western entrance of the Hutt Valley, is supposed to be either Zheca or 
Dentalium; and some vermiform casts, probably Zentaculites, have been 
found at the same place. 
.. The most frequent remains of organic life, however, are to be found as 
pcd 
