210 
detail all the anatomical characteristics of Anopheline larvae of this 
region ; that has been done for some species by Knab. The chief 
anatomical differentiating larval characters of the common Anophe- 
lines of this region are these: — 
Ce. albimana or white- Palmate hairs on all abdominal segments Antennae without a tuft 
footed group and sometimes on postcro-external of hairs 
angle of thorax 
A. psendopunctipennis Palmate hairs on third, fourth, fifth, Antennae without a tuft 
group sixth, seventh abdominal segments, of hairs. 
but none on the first and second. 
On the latter two, however, there 
is a rudimentary stalked tuft. 
Arr.(f) malefactor, or spotted- No palmate hairs on first and second Antennae with a tuft 
legged group abdominal segments, but palmate of hairs. 
hairs on all remaining segments. 
These characters are very striking and sharply separate the 
groups, thus separating the malaria-transmitting Ce. albimana 
group from other varieties. With care it is frequently possible, even 
in muddy water, from an examination of the indentations of the 
surface film caused by the palmate hairs, to at once determine the 
presence or absence of members of the albimana group. In the 
latter group there is no break in the indented film, but in the two 
former groups there is a well defined non-indented break in the film, 
due to the lack of palmate hairs on the first and second abdominal 
segments. 
1 he size of the palmate hairs on the postero-lateral angle of the 
thorax and the presence of these hairs on the thorax, first and second 
abdominal segments, is subject to some variation. It would seem 
that the white hind-footed group are undergoing some variation 
witli regard to the size and location of these hairs and apparently 
they are becoming rudimentary or vestigial on the thorax and first 
abdominal segment. 
FOOD OF ANOPHELINE LARVAE 
The generally separate and distinct breeding places cl 
Arr. (?) malefactor and Ce. albimana, for instance, naturally 
suggest that their food might also be different. Dissection of 
specimens of A. psendopunctipennis and Ce. albimana in all 
instances discloses much green algae in the intestinal tract, while 
