( ?3 ) 
Madam, D. Ganting, D. Babai, D. Kambat etc.) cut off by con¬ 
striction, which have become black waters. Similar swamps also 
occur along the Kahajan. W. J. M. Michielsen found fens along the 
Sainpit and Katingan rivers. 
The extensive swamps in the southern part of the Western division 
in the Kandawangan country have not yet been examined. The 
names of two rivers, Ajer I tain besar and Ajer Itam ketjil, indicate 
however that fens are present. This is also the case near Simpang, 
where the Sungei Itam and the Dulah Sidok belong to the black waters. 
f . The great Kapuwas river is rich in fen formations. Near the 
mouth a Sungei Itam is found, and swamps occur behind Pontianak. 
The lakes along this river, which have arisen in the same way as 
those along the Barito, belong to the black waters. Peat strata Were 
observed along the Kapuwas by G. A. F. Molengraaff and near 
the Kenepai by J. E. Teyssmann, who also found, that the swamp 
behind Sintang is a fen. The lake region of the Danau Luwar etc. 
is also in a state of fen formation. Similarly fens seem to occur along 
the lower reaches of the Sambas river. A high peat-bog was discovered 
by G. A. F. Molengraaff in the Babas Hantu, 1036 metres high, 
in the Madi mountains. 
In Sarawak an extensive swamp was shown to exist by Charles Hose 
between the Madang and Kalabit districts (lat. 3 Q 16 — 3°20' N., long. 
115 24 — 115°38' E.) and another one in the Western part of the 
Kalabit district (lat. 3 28' — 3°45' N., long. 115°24' — 115°42' E.). In 
Northern Borneo there is, according to Frank Hatton, an extensive 
fen in the Lamag district, belonging to the basin of the Kinebatangan 
(lat. 5°13'—5°23' N., 117°52'—117-56' E.). 
Finally New Guinea is very rich in fen formations. Whereas they 
appear to occur somewhat sparingly in the northern part (Kaptiau 
on the Borowai and in the territory x between the Geelvink Bay and 
lake Jamur, also near the Sele Straits), extensive strata occur in the 
south-western and southern parts of the island. They were found 
near the Noord-, Reiger-, and Dumas rivers by J. W. van Nouhuys. 
A sample contained only 4.58% of ash. 0. E. Heldring has traced 
the distribution in the* neighbourhood of Merauke. These investigations 
extend from the coast to lat. 7°32' S. and it results from the survey, 
that of this part 224000 hectares are covered with fens. Many of 
ihe rivers which have their mouths on the South coast, such as the 
Wamal, Bulaka, Bemt, Sewa, Koroi, Bian, Toran, Kumbe, Marau 
and Torasi should be reckoned among the black waters. 
Whereas the composition of the peat-bogs of temperate and cold 
regions has been subject to many changes, in consequence of the variations 
