ABDOMEN OF FEMALE 67 
veloped it is hairy and particularly on the apical half the hairs are long and 
stiff. The pulvilli, a pair of fleshy lobes present on the feet of the higher flies, 
are absent in the Culicids, as in most other Nemocera. Ficalbi wrongly showed 
pulvilli in the foot of the mosquito and has been followed in this by Blanchard 
and others. The error is based upon a misinterpretation of the cushion just 
described. 
The empodium is an unpaired organ arising between the claws. It is usually 
slender and tapers outwardly into a bristle and bears a number of sete. It 
differs much in length and development and may even be absent altogether. It 
is, however, well developed and long in the front feet of the male Anopheles, 
where one claw is rudimentary ; but in this case it is inserted at a considerable 
distance behind the large claw. In Lutzia bigotii it is broadly compressed, with 
a setose margin; at the base of the claws, externally are a series of long sete, 
the whole forming a mechanism to enable this large mosquito to rest upon the 
water. In Culex melanurus the empodium has the form of a chitinous plate 
the outer margin of which is produced into a series of long spines. 
THE ABDOMEN. 
The abdomen is elongate, more or less cylindrical, and is composed of ten 
segments. Of these the first eight are similar in character while the last two are 
greatly reduced and modified for the sexual functions. Each of the first eight 
segments consists of chitinized dorsal and ventral plates, the tergum and 
sternum ; these are connected at the sides by a broad area of flexible membrane 
which is folded when the abdomen is not distended. The segments are con- 
nected with each other by flexible membrane which is normally retracted in such 
a manner that each segment projects over the succeeding one. There are six 
pairs of abdominal spiracles. These are small and situated before the middle 
in the pleural membrane of the second to seventh segments. The first segment 
is shorter than the succeeding ones and its tergite bears many long hairs upon 
its surface. 
THE ABDOMEN OF THE FEMALE, 
The oviduct opens in the membrane behind the eighth sternite; the orifice is 
large and is surrounded by chitinous strips. The ninth segment is small and 
bears a small chitinous tergite while the sternite is carried outward and pro- 
jects beyond the tenth segment. The ninth sternite bears a pair of gonapophyses 
which are variously developed. They may be nearly obsolete, represented by a 
pair of blunt tubercles; in other forms they are long and slender and bear many 
coarse hairs. The tenth segment is greatly reduced, without tergite or sternite ; 
it bears the cerci and in it is the anal opening. The cerci are not jointed, but 
present great variation in form and size. There is often present a third chitinous 
appendage which apparently also belongs to the tenth segment ; in certain forms 
this is large and of nearly equal length with the cerci and may be emarginate at 
the apex. The general form of the abdomen of the female differs greatly, and 
correlated with this difference is the form of the terminal appendages. To a 
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