240 
pushed out sidewise to allow the hypo- 
pharynx to coalesce with the labium. 
In the male the oesophageal pump, or bulb 
behind the nerve-ring, fails, and the suck- 
ing of fluids must be done by the phar- 
ynx alone, as it is done in most diptera. 
The labrum-epipharynx is nearly the 
same in general form and structure in 
the male Culex as it is in the female, it 
is a trifle longer and slenderer, but the 
same figures (5 l7-e, and 6) will serve 
for the tips of both. In section (fig. 
12, lr-e), the labrum shows a groove on 
its upper surface, which deepens as it 
nears the base (fig. 13, Jv-e). The api- 
eal four-fifths of the labium contains no 
other seta than the labrum-epipharynx, 
as seen in fig. 12, which is a section at 
about the middle of the proboscis. At 
the base of the labrum-epipharynx are 
pharyngeal muscles similar to those 
found in the female, and with similar 
insertions and origins, except that the 
median muscle (fig. 15 pm’) is not di- 
vided into three parts as in the female 
(fig. 9, pm’). 
The hypopharynx is, throughout its 
whole length, joined to the labium, and 
thus necessarily pushes the maxillae, 
which would normally lie between it and 
the labium, to one side. (See fig. 13, 
hand mx.) The hypopharynx shows, 
in section (fig. 13-15 h), the same chi- 
tinous rod through the middle as in the 
females, but I was unable to detect any 
channel for saliva through this rod. 
The maxillae are very thin lamellae 
of transparent chitin, about one-fifth 
as long as the labium, and so delicate 
as to be easily overlooked. Although 
as broad at the base as is the tube of 
the epipharynx, they taper regularly 
PSTCHE. 
from their base to their fine tips. 
The maxillary palpi are five-jointed, 
very hairy toward the tip, much longer 
than they are in the female, and when 
at rest their basal portions cover the 
labrum-epipharynx and maxillae in the 
sheath of the labium. 
The labium of the male Culea is simi- 
lar in general structure to that of the 
female, if one considers it together with 
the hypopharynx. It is, however, slen- 
derer, more densely covered with scales, 
has a shallower groove for the reception 
of the labrum-epipharynx, and has a 
joint near the middle. The slenderness 
of the labium in the male extends itself 
to the labellae. (Compare fig. 4, Jb 
with fig. 5, /b.) The groove of the 
labium of the male increases in shallow- 
ness from tip to base; at the middle of 
the proboscis (fig. 12) it is so shallow 
that it fails to fully protect the labrum- 
epipharynx, and at its base (fig. 13) it 
is so shallow that the other mouth-parts 
rest only on top of the labium. To 
make up for this deficiency of protection 
by the labium, the maxillary palpi, as 
was previously mentioned, cover over 
the upper side of the enclosed parts 
(see fig. 13), and thus, although free 
from the labinm, form a part of the 
protective sheath, which, in the female, 
is formed by the labium alone. Wheth- 
er the joint near the middle of the labium 
of the male Culex is true or false I can- 
not say, since I have never seen it bent 
by the insect itself; its appearance is 
that of a true joint. Like the labium 
of the female, that of the male has two 
longitudinal main tracheal stems (figs. 
12-14, tr), and two rows of longitudi- 
nal muscles. 
