Fauna and Flora of New Zealand. 435 
14,000 or 15,000 feet, that is 2500 fathoms. Now it is fair 
to suppose that when the immense mass of Chili, part of Peru, 
La Plata, and Patagonia was depressed 2500 fathoms below 
its present level, a compensating elevation may have occurred 
in the South Pacific Ocean, and that as South America rose 
the bed of the Pacific sank. If this were the case, the South- 
Pacific continent must have been in existence in the Jurassic 
and Lower Cretaceous periods, and begun to subside in 
the Upper Cretaceous. The lowest portion, that between 
Samoa and the Society Islands, would have been submerged 
first, and the connexion between New Guinea and South 
America may have been severed before the close of the Cre- 
taceous period. This conclusion agrees very well with that 
drawn, quite independently, from a study of the Australian 
fauna and flora. 
On the western side of the South Pacific the oscillations of 
the land appear to have been much less. Of the geology of 
New Guinea it is known that Jurassic rocks are largely deve- 
loped both in the north and in the south, which indicates that 
the land then stood at a lower level. No Cretaceous rocks 
are known from any part, and at this period therefore it may 
have been upheaved. ‘Tertiary clays and limestones occur at 
Hall’s Sound and at Yule Island; but as, according to Mr. 
Tenison-Woods, the fossils have nothing in common with 
those of Australia, their age remains at present doubtful *. 
New Caledonia consists principally of two rock-systems, 
one of older Paleozoic, the other of older Mesozoic age. Ac- 
cording to M. Garnier, Lower Cretaceous rocks are also found 
there; but the evidence appears to consist of a single fossil 
(Pinna) only. 
In Eastern Australia and Tasmania the main range of 
mountains is formed of contorted schists and slates of Lower 
Paleozoic age. In New South Wales the denuded surface of 
these rocks is covered by enormous masses of shales and sand- 
stones of Upper Paleozoic and Lower Mesozoic age, lying in 
a nearly horizontal position and forming the upper portions 
of the Blue Mountains. Further to the north, in Queensland, 
this system is overlain in places by rocks of Jurassic and Cre- 
taceous age. Jurassic rocks are also found in Tasmania, 
Victoria, and in Western Australia; consequently we must 
suppose that during this period Australia was more depressed 
than at present, although not altogether submerged. During 
* Mr. C.S. Wilkinson believes them to be of Lower Miocene age (Proc. 
Linn. Soc. N. S. Wales, vol. i. p. 114). For Mr, Tenison-Woods’s 
opinion see the same publication, vol. vii. p. 882. Formerly he con- 
sidered them as probably older Pliocene (/. c. vol. ii. p. 127). 
