DIPTERA. 339 



and bilobed at the tip ; legs of the opposite sides in- 

 serted down the middle of the thorax ; head and thorax 

 distinct, being connected by a neck; antenna placed 

 between the eyes. 



In EPROBOSCIDEA, the proboscis is tubular, the legs 

 are set wide apart, those of opposite sides being separated 

 by a wide breastplate. The head is either sunk in the 

 thorax, or thrown so completely backward as to be 

 actually reversed, and the antennae are partially buried 

 in the head. 



The first section, PROBOSCIDEA, is divided into two 

 large groups, named, from the characters of the antennae, 



1. NEMOCERA. 



2. BRACHTCERA. 



To this is added a third, HYPOCERA, which consists 

 but of one genus, containing only a few small species. 



To NEMOCERA belong the Gnats, Daddy Longlegs, and 

 others, having long and slender thread-like antenna of 

 several joints, numbering from six to sixteen, and fre- 



Fig. 69. 



Antenna of fiptik. 



quently very beautifully decorated with whorls of long or 

 short slender hairs (see fig. 59, and PI. XI V_, fig. 1). 

 The Flies of this division are nearly all to he recognised 



Z 2 



