DU. S. H. LONG ON THE MOSQUITO-MALARIA THEORY. 195 
In Anopheles, the palpi, in both male and female, are as long as 
the proboscis ; in Culex, the palpi in the female are much shorter 
than the proboscis. There are several other minor points of 
difference, but this difference in the length of the palpi is easily 
seen by the naked eye, and serves as a ready means of differentiation. 
The Anopheles maculipennis has four black spots on each wing 
Anopheles 
arranged in the shape of a T, the horizontal bar of which is partly 
wanting. This is also easily recognised by the unaided eye, and 
can be seen in the mounted specimens of the insect I will hand 
round to you. 
Another means of distinguishing the Anopheles from Culex is 
by observing the position of the insect in the resting state. In 
Culex the head and thorax form an angle with the rest of the body, 
giving the insect somewhat of a hump-backed appearance ; whilst 
when Anopheles is at rest, the head and thorax and the rest of the 
body are in one straight line. This is seen in the diagrams I show 
VOL. VII. 
o 
