340 INSECTS. 



with ease by their slender form, small head, high thorax, 

 and long and delicate legs, which are extended down- 

 wards and backwards during flight. 



Fig. 70. 



Female Gnat (Culex Pipiens) at rest. 



In BRACHTCERA the antennae are comparatively short, 

 very often consisting of only three joints of unequal 

 size, from the last of which a bristle or delicate feather 

 usually springs (see PI. XIV., 6, a; XV., 4, a; XVI., 

 3, a, 5, a). The antenna sometimes are longer and 

 have more joints (see PI. XIV., 2, a, 4, a) sometimes 

 as many as ten but these, after the third, are usually 

 more or less consolidated into one, and have a character 

 different from that of the distinctly articulated antennae 

 in Nemocera (see fig. above). By far the greater 

 number of Flies belong to Brachycera. 



In the small section HYPOCERA, the antennae much 

 resemble those of the Brachycera, but are differently 

 placed, being low down and close to the mouth. The 

 character of the mouth, in which the lancets are not 

 developed,with some other characters to be named in their 

 place, also help to distinguish it from Brachycera. 



The wings in Brachycera are usually characterized by 

 the posterior nerves forming several perfect cells.* In 

 most families the membrane of the wing forms a larger 

 or smaller lobe in the axil, which lobe is very small 



* See figures in table of Diptera. 



