254 TREUBIA VOL. II, 2—4. 
voracious and feed on live prey only. Small worms, young fry and mosquito- 
larvae are their favourite nutriment...... 
SYBRANDI (°7) also thinks he has observed that “the appearance” 
(of the little white spot on the head of the kepala timah) “is not attributable 
to the intensity of the light alone”. 
Further SYBRANDI (%) mentions the power of the amorous male of 
varying its colours at discretion within certain limits. This is to be accounted 
for from the well-known fact that the melanin- and lipochrome-chroma- 
tophores discussed above, are able to expand their pigment containing 
cell-body in an amoeboid manner and inversely to contract it into a minute 
ball. SYBRANDI (%) describes the colour of the kepala timah as greyish 
(or sallow-grey, “vaal grijs”) under normal circumstances. Judging from 
my Haplochilus panchax (HAM. BUCH.) originating from the Batavia empangs, 
the description as “greyish”? does not seem to me very fortunate in this 
instance. But I think it is sufficient for me to refer to my observations 
and remarks higher up on the colours of the kepala timah, originating 
from the Batavia empangs. 
SYBRANDI (°7) further says that the anal fin in the female kepala timah 
is “shorter” than in the male. This question resolves itself into the 
following facts: 
In both the male and the female the anal fin has the same number 
(usually 17) of fin-rays. On the whole however the fin rays are far more 
branched in the male than in the female, especially in the caudal half of 
the anal fin. Moreover in the female it is the 7th, 8th and 9th rays of 
the anal fin that are longest, whilst in the males the successive rays increase 
in size up to the 14th or 15th ray. In accordance with this in the female 
the postero-distal end of the anal fin is rounded off, whilst the same 
extremity in the male grows to a point. 
CHAPTER VII. 
The Anopheline larvae of the Batavia empangs. 
The data dealt with in this chapter were collected in 1918 and 1919, 
partly by the then Chief of the Public Health Service (Chef van den Gezond- 
heidsdienst) at Batavia, Mr. M. L. VAN BREEMEN, partly by myself. 
Mr. VAN BREEMEN and his staff determined and counted the female ') 
Anophelines caught with mosquito-nets and hatched out of larvae and 
pupae collected. In the places where the mosquito-nets had been set and/or 
the larvae and pupae had been caught, care was taken each time to also 
oy An the case of Anophelines it is often easier to determine the females than the 
males, because for the distinction of the species it is often convenient to go by the 
characteristics of the female palpi. 
