On a Simulium-larva from a mountain-current 
of the Gunung Pangerango. 
(Summary.) 
In May 1917 I found in one of the mountain-currents of 
the Gunune PANGERANGO, at a level of about 1000 M. + 2000 
larvae of a Simulium-species clinging to a submerged stone 
and covering together a surface of about 6 dM?. 
From the movements of the living animals which I could 
observe and from the structure and situation of the two 
clinging-organs and of the spinning-glands I conclude 
that both clinging-organs are exclusively anchored in a lock 
of silk-threads which are spun and fastened to the substratum 
previously. Without the aid of the silk neither of the two 
clinging-organs can functionate. 
From the structure and the situation of the fans and the 
mouthparts it is evident that the fans act as strainers 
retaining all sorts of fine microscopic food particles which 
are carried along by the current and the mouthparts as brushes 
by whose action the fine food-particles are brushed from the 
closed fans into the mouthcavity. The fans are certainly not 
whirl- organs since the possession of a rotatory-organ by an 
animal living in streaming or rather quickly running water 
would have no sense at all. 
The contents of the gut of the larvae consisted firstly of 
fine vegetable detritus from higher plants, secondly of Diatoms 
and thirdly of a piece of the ectocyst of a Bryozoin-colony 
and some few rests of a very little Arthropod. _ 
As far as I know larvae of Simulium had not yet been 
found in Java up till now. Only a few imagines of six 
different species of Simulium were collected bij Enw. JACOBSON 
in the mountain-regions of Java and were afterwards described 
by de Mevere. Konryessercer too collected a few imagines 
of Simulium in the mountain-forest of the Gununa GEDEH. 
