570 H. A. BROUWER 
coral islands and reefs, from which the islands emerged which are 
now the higher mountain groups of the present much enlarged 
island. 
A similar stage of evolution is now to be observed in the same 
range of islands more to the east. The islands of the Sermata group 
clearly illustrate the movements of reefs in the period of develop- 
ment of the geanticline in which only its highest parts emerge 
from the sea as a group of smaller islands. The island of Luang 
has an altitude of 260 m. and, according to my observations, is built 
up entirely of Permian rocks. Together with two small islets at 
its southeastern extremity, it is fringed by a very broad reef, 
extending far to the east in the direction of Sermata and far to 
the west as well. Green islets far from the north coast, and barren, 
dry portions far from the south coast, mark the limits in northern 
and southern direction; beyond them the sea floor declines rapidly. 
Luang as well as the two small islets close to it rise up steeply from 
this broad reef, and no trace of elevated reefs was detected; the 
islands impress us as having originally formed one continuous 
whole and as having been separated by a positive movement, which 
may also account for the formation of the broad encircling reef. 
In its eastern part the island of Moa consists of a low, very 
broad plateau of coral limestone, which rises scarcely more than 
10-20 m. above the sea. From this plateau rises the steep Kerbau 
Mountain to an altitude of 4oom. Elevated reefs are lacking on 
the slopes of this mountain, and if the eastern part of Moa were a 
little lower, this region would present an aspect similar to that of 
Luang. The Island of Lakor, between Luang and Moa, consists 
of a low coral plateau, and Meaty Miarang forms the southern 
part of a large atolliform reef on the northern part of which lie the 
two low Ukenaé Islands. To the east of Luang and to the west 
of the eastern part of Moa the reefs are elevated to much greater 
altitudes and the group of the Sermata Islands shows a well-marked 
depression of the geanticlinal axis of the Timor-Ceram row. ‘This 
part is much disturbed by transverse fractures and no sufficient 
data are available for judging whether the submersion observed on 
some islands is the consequence of the pitch of the geanticlinal 
axis only, or whether this region has passed, or will in the future 
