SUNIER: Marine fish-ponds of Batavia. 195 
Besides Chaetomorpha, Ruppia rostellata, Enteromorpha and Najas 
falcieulata as the chief components of the submerged vegetation, 
there is also Vaucheria (Chlorophyceae, Siphonales, Vaucheriaceae) which 
occurs not infrequently in the Batavia empangs. Vaucheria is indeed the only 
alga (“lumut”) mentioned by VAN KAMPEN (2). This, however, must be 
due to some accidental circumstance, for the part played by Vaucheria in 
the Batavia empangs is not comparable with that played by Chaetomorpha. 
I always found Vaucheria in the Batavia sea-fish ponds in the shape 
of black-green sods resting on the bottom, which I could often discern at 
some distance as black patches visible through the water, and whose 
diameter was a couple of metres or less. Thus on April 27th 1918 
in pond E of Map II I found Vaucheria-sods in water of a salinity of 
19.2°/,,; on July 16th following the Vaucheria patches were still in 
existence there, the salinity then amounting to 36.5 °/,,. On August 12th 1919 
I found Vaucheria not only in pond E of Map II at a salinity of 35.9 °/,,, 
but also in the ponds B and C of Map Il at salinities of 26.7 °/,, and 37.7 go 
respectively. Also at Tjilintjing, on July 2nd 1918 I found Vaucheria in 
two different ponds. 
Vaueheria did not occur in the samples of algae drawn from the Batavia 
empangs, whose composition is mentioned in the observation-table (Table IV). 
Also Spirogyra (Acontae-Conjugatae-Zygnemaceae) is of regular occur- 
rence in the Batavia empangs. I came across Spirogyra much more 
frequently than across Vaucheria when examining samples of algae drawn 
from the Batavia empangs; yet I never found large coherent masses of 
Spirogyra, at all comparable with the Chaetomorpha-masses or even with 
the sods of Vaucheria. | often found an occasional filament of Spirogyra 
among the Chaetomorpha filaments. 
As to the occurence of Spirogyra at a definite time, place and saints my 
diary (1918) and the observation table (Table IV) (1919) yield the following 
further data: 
12 "19; Pond near Muara Karang; 4.4 °/oo- 
15 VIII °19; Pond near Heemraad-Oost; 10.5 P/oo- 
SNES Pond (G) of Map Il; 143 an. 
16 IV ’18; Pond G of Map II; NOE Sa 
2 VII ’18; Pond near Tjilintjing; ZO ican 
32 4.195 Pond i near :MuararKaranoı;) 3:37.00. 
5 V 19; Pond near Heemraad-Oost; 10.0 °/, 
7 V ’19; Pond near Muara Karang; 12.9 °/go- 
8 V ’19; Pond near Muara Karang; 4.7 ®/, 
9 V ’19; Pond near Muara Karang; 4.2 °/o. 
10 V ’19; Pond near Muara Karang; 4.35 °/go- 
NEO Pond near MuaraKaranes 7 3:95 00: 
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