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most 75 m. below the sea-level; on the edge of the Spermonde Bank 
a barrier-reef has developed, which as to distinctness, is not inferior 
to the Great Sunda Barrier-reef, while the Spermonde Shelf, like the 
Borneo Bank is studded with a great number of reef-structures, which 
occasionally reach the surface of the sea. The Spermonde Shelf termi- 
nates abruptly at 4°16’ south latitude and the Spermonde Barrier-reef, 
which can be traced, although with interruptions, towards the north 
over a distance of 230 km., as a row of coral-islands, here gets 
attached to the coast-reefs; more to the north the coast of Celebes 
possesses only insignificant fringing-reefs. 
It seems as if the history of the west-coast of South-Celebes in 
recent geological time has been similar to that of Sunda Land, 
contrary to the other parts of Celebes. 
4. The Laars Banks and the atoll Bril. 
The coral-islands, known as the Laars Banks and the atoll Bril, 
situated in the channel connecting the Strait of Macassar with the Flores 
Sea, warrant the assumption that this strait has become deeper in 
post-pleistocene time. The Laars Banks constitute together a composite 
atoll. The reef-structures form a ring with large gaps. They rest on 
a base which lies more than 100 fathoms deep, but is for the rest 
almost entirely unexplored. In the northern part the reefs have 
grouped themselves into a separate ring or ‘‘faro”, which atollon is 
charted under the name of Laars-islands. The coral-islands of the 
Laars Banks have presumably originated in the same way as 
those of the Kalu Kalukuang Bank; it would seem then that formerly 
the Laars Bank was located at the same depth as the Kalu Kalukuang-, 
or the Paternoster-bank and like the latter belonged in the beginning 
of the Pleistocene as an island to Sunda Land. After the Pleistocene, 
however, the bank on which the Laars-atoll rested, subsided with 
the deepening of the water that unites Strait Macassar with the Flores 
Sea, and the coral-formations could only here and there, by upward 
growth maintain their position at or near the surface of the sea. 
The origin of the atoll Brill may be explained in the same way as 
that of the Laars-atoll. | am also inclined to believe that the Zand- 
buis-atoll and its lagoon with depths of more than 100 fathoms is 
founded on a bank which has subsided as late as the post-pleistocene 
time. 
Oscillations of the sea-level in recent and subrecent time. 
From the position of the terminal moraines and from other 
peculiarities of the territories that have been evacuated at the final 
