4f>' A Monograph of Culicidae. 
are quite black, and they appear not unlike very small safety 
matches floating on the water.” The larvae often lie for a long 
time in this horizontal position, but now and then slightly moving 
themselves on by bending the body. When watched carefully, they 
are seen to be sluggish and dull in habits, very different to Culex , 
but when disturbed they dart down in the water and sink to the 
bottom, but soon, however, regain the surface, rising by quick 
bending movements of the body, in a series of jerks, but, as a 
rule, we see them moving from one place to another of the 
aquarium in an oblique direction, these jerky movements along 
the surface of the water being very characteristic. It is wrongly 
supposed, as pointed out by Meinert, that Anopheles larvae move 
horizontally as in Corethra. They sometimes may be seen lying 
on the floor of the pool, both on their venter and dorsum. 
When disturbed the larvae wriggle tail first to the bottom of 
the water and there remain for a few minutes, when they ascend 
tail first to the surface again. I have noticed that they may 
remain beneath the water some time, botji at the bottom and at 
the sides of the jars in which they were kept. About half an 
hour seems their limit, however, of submergence. 
Like Dixa larvae they have the peculiar habit of being able 
to turn their head completely round; often when feeding they 
lie in the normal position but the head is turned upwards to the 
surface of the water. This movement is done very rapidly, and is 
always followed by violent movements of the vibratile organs 
surrounding the mouth, thus setting up a miniature whirlpool over¬ 
head. Their food is mostly of a vegetable nature, but all manner 
of small organisms are swept into the mouth by these whirling 
vibratile structures. They also to some extent show carnivorous 
habits, for Dr. St. George Gray in one of his communications 
states that in those he had under observation (A. argyrotarsis , 
Desvoidy) cannibalism sometimes occurred. Captain James 
reports that they can often be seen feeding on the small green 
plants in the water, which evidently form their chief diet. 
Drs. Christophers and Stephens found that the food of 
Anopheles larvae, in the majority of specimens examined by them 
at Accra, consisted of an unicellular organism (protococcus ?). 
This is endorsed by Professor Howard, who noticed that 
his larvae flourished best on green algae. Mr. F. K. Woods, 
of the Division of Vegetable Physiology, found the algae to 
belong to the genera Aedogonium, Cladophora , Spirogyra and a 
few Oscilaria. 
