14 
A Monograph of Culiciclae. 
When denuded, the surface of a mosquito is smooth, often 
shiny and either steely black, ferruginous, or yellowish grey in 
colour. The scales alone give the beautiful appearance to these 
insects. The genus Megarhinus shows the most brilliant colours, 
which vary in hue and intensity with every different ray of light 
that strikes them, making a description extremely difficult to 
compile. The colours produced by these scales are due entirely 
to the refraction of the rays of light, and not in any way to 
colour pigments, the scales being often quite transparent when 
detached and examined under the microscope; some few, how¬ 
ever, that I have seen contain a brown pigment similar in colour 
to that of the spots on the wings in such forms as Mucidus 
alternans , Westwood, and some Anopheles a jet black pigment. 
In the following descriptions I have tried to point out some of the 
varied hues a species has when held in different positions, which 
must be an essential feature in the description of all Ciilicidae. 
In a casual description one would describe, say, the legs as black, 
reverse the insect and you will find them purple or violet. 
ADULT CHARACTERS OF THE FAMILY CULICIDAE. 
The characters of the family Culicidae may be summed up 
as follows :— 
Head small and more or less rounded, the occiput covered 
with scales; eyes reniform ; ocelli absent; mouth in the form of 
a proboscis wffiich is usually 
very elongated and formed of 
the following parts : (1) a long 
pointed upper lip or labrum, 
united with an accessory piece, 
the epipharynx; (2) a long 
gutter - shaped lower lip or 
labium, ending in two jointed 
spatulate labella which appear 
to be the labial palps; (3) two 
narrow needle-like mandibles ; 
(4) tw r o thin maxillae, ending 
in serrated or barbed edges; and 
(5) a single piece of extreme 
thinness, the so-called liypo- 
pharynx ^ the whole being enclosed by the upper and lower 
lips (Fig. 10). In one section the proboscis is short and fleshy 
y E P 
Transverse section of proboscis (after 
Dimmock). 
Fp., labrum - epipharynx; Hy., hypo- 
pharynx ; md., mandibles ; mx., maxillae ; 
L., lower lip (labium). 
