2 
A Monograph of Culicidae. 
(1.) The head (Fig. 7, III.).—The head is joined to the 
thorax by a narrow neck. It varies greatly in form in different 
groups, but its general structure is the same throughout all the 
genera of the family Culicidae. 
That portion of the head lying nearest the neck is spoken of 
as the occiput (Fig. 7, III. oc), and is always more or less 
clothed with scales of vai’ious forms, the hindermost portion of 
the head being known as the nape or cervix (n) ; in front the 
major portion is taken up by the large compound eyes, which 
may or may not meet in the middle line; the space between the 
eyes and antennae is called the frons (f), whilst the space 
directly between the eyes at the isthmus joining the frons and 
occiput is called the vertex or crown (v); the part of the head 
that lies on the side beneath the eyes is called the gena or cheek; 
in front will be seen a more or less firm chitinous prolongation, 
the clypeus (Fig. 7, III. c, and Fig. 3). The compound eyes are 
nr it i 
Fig. 3. 
Types of clypeus. 
I. Culex. II. Stegomyia. III. Tmclioprosopon. 
large and usually reniform, surrounding more or less the base 
of the antenna?, and are usually brilliant in colour when alive ; 
no ocelli can be detected. 
The antennae (Fig. 7, an) arise from the frons; the basal 
joint (f) is large, round and may or may not be provided with 
scales ; this basal joint is cup-shaped, and in it fits the second 
antennal joint, which may be long or short; in the female the 
antenna (Fig. 12, 1) will be found to be made up of fourteen 
joints, the bases of the joints being constricted and usually paler 
in hue; just above the base or in the middle of each joint arises 
a band of long, moderately thick verticillate hairs; sometimes 
besides these, each joint has numerous smaller hairs, or a second 
row of smaller verticillate hairs; in the ^ the bases of the joints 
are more oval and-swollen, and the last two joints are very 
long, whilst the verticillate hairs are more dense, and are spoken 
of. as being plumose. 
