73 
head, the front part of which is only half the width 
of the posterior portion. On the last segment there 
is a swimming fan. There is no respiratory syphon. 
They lie horizontally rather deep in the water and are 
extremely voracious (Fig. 25). Add some Corethra 
larvae to a glass of water containing Culicine larvae and 
watch the result ! 
The Larvae of Anophelines 
To collect the larvae .—Necessary apparatus :— 
1. An ordinary spoon. 
2. A white enamel tin or large cup, or an ordinary 
bath tin. 
3. Bottles, specimen tubes, paper, pencils, etc. 
1. By inspection .—Inspect closely the surface of 
any small puddles that have been in existence some 
time. Examine especially small rock puddles, small 
shallow pools in 4 nullahs 5 and river-beds, in the dry 
season. 
Examine especially the edges where larvae are fond 
of resting, with the head facing the open water and the 
tail touching the bank. Note also how larvae tend to 
cling to floating twigs, etc. If no larvae are seen, stir 
up vigorously the bottom of the pool with the spoon. 
This will dislodge larvae from the edges, etc. 
Examine the surface of the pool again and observe 
the larvae now plainly visible against the muddy water. 
Wait a few minutes for the appearance of the larger 
larvae, which remain below longer than the younger 
forms. Examine carefully for nvmphae, which easily 
escape detection. 
Dip out the larvae and nymphae with the spoon 
as they appear. The thinner the edge of the spoon the 
