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 Culicidge, as in most other Nemocera. Ficalbi wrongly showed 

 pnlvilli 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 sets. 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 higotii it is broadly compressed, with 

 a setose margin; at the base of the claws, externally are a series of long setae, 

 the whole forming a mechanism to enable this large mosquito to rest upon the 

 water. In Cidex 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 



6 



