3 
External Structure of a Mosquito. 
The mouth of the Culicidae consists of a distinct proboscis 
composed of the following eight pieces:—The upper lip and 
epipharynx ; two lancet-like pieces, the mandibles ; two other 
delicate needle-like organs barbed at their summits, the maxillae ; 
a thin tubular thread, the so-called hypopharynx, and the lower 
lip. As these parts are of little specific importance they are 
only briefly referred to. 
The labrum, or upper lip, extends nearly to the tip of the 
proboscis, forming an upper sheath for the lancets, and has 
hy-_ 
Fig. 4. 
Diagram of the mouth-parts of a 9 Mosquito. 
mx = maxillae ; md = mandibles ; u. 1. = upper lip and epi¬ 
pharynx ; 1. 1. = lower lip ; e = labella ; hy = hypopharynx 
closely united to it a piece, the epipharynx m (Fig. 10) ; the 
mandibles and maxillae form four lancet-like pieces beneath it, 
and between them and the upper lip lies the hypopharynx, a 
small needle-like thread, connected with a poison gland (Fig. 5, c) 
at its base; the whole of the above are enclosed by the canal¬ 
shaped lower lip, which, however, is open above, the opening 
being closed by the upper lip ; at the end of this lower canal 
* The term epipharynx had 
upper lip. 
best be abolished, as it is really part of the 
b 2 
