30 E. C. ANDREWS. 
been described in a previous paragraph, possess no raised 
reefs. 
Lau, or eastern Fiji, is an unstable area and shows suc- 
cessive terraces of raised reefs of Pleistocene Age. If it 
be considered as a unit it has the form of an earth undula- 
tion whose highest point is at Vatu Vara in the centre, 
and which pitches thence north and south as well as east 
and west. The atolls lying on the subparallel zone to the 
east indicate the marked influence of the easterly pitch of 
the earth wave. 
Tonga.—The volcanoes which form the western zone of 
the group appear to rise from a submarine platform of 
moderate depth. This is unstable as compared with the 
western line of Fiji, New Caledonia, Hastern Australia, 
and Western Australia, and is of recent growth. The belt 
of elevated coral reefs known as Vavau, Haapi, Namuka, 
and Tongatabu, is of Pleistocene Age and lies within a 
very unstable area, the southern and the northern extremi- 
ties being elevated in much greater degree than the central 
portions. The atolls of the Tonga Group lie in the centre 
and in the westerly portion of this long wide zone. This 
is in decided contrast with the internal arrangement of 
Lau in Fiji. 
(5) The Relative Stability of the Individual Groups 
considered progressively in space from Australia to the 
Paumotus.—Australia is the oldest and most stable block. 
It is, moreover, the block which has been stable during a 
greater period of time than the eastern groups. Further- 
more the western portion is more stable than the eastern. 
A fine example of a continental shelf has been developed 
around the continent. 
New Caledonia, with the Loyalties, forms a group of less 
‘stability than Australia. New Caledonia, however, appears 
