252 MANUAL OF NATURAL HISTOEY. 



thorax compact, prothorax very short, fixed immov- 

 ably to mesothorax ; wings two, anterior membran- 

 ous, not scaly, variously veined, with produced lobes 

 or winglets at the base ; hind- wings replaced by 

 small clavate appendages or balancers ; tarsi 5- 

 jointed. 



I. SUB-ORDER. — Proboscidean-Flies (Proboscidea). 



Head distinct from thorax ; legs close, side by 

 side ; claws of tarsi not dentate ; larva not under- 

 going its metamorphosis within body of parent. 



I. TRIBE. — Slender-horned Flies (Nemocera). 



Antennae composed of more than six joints; palpi 

 4 or 5-jointed ; pupa incomplete. 



1. Family. — Leaping-Gnats (Mycetophilidae). An- 



tennae slender, 15 or 16-jointed, longer than 

 head, compressed, never fasciculated ; last 

 joint of palpi not ringed ; ocelli two or three, 

 unequal ; head not rostrate ; coxae elongated ; 

 hind-tibiae spined, mostly with long spurs. 

 Fungivorous ; capable of leaping by means 

 of their hind-legs. 



2. Family. — Gall-Gnats (Cecidomyidae). Antennae 



more or less moniliform, of 13 joints, simply 

 ornamented with a few verticillate hairs; 

 eyes lunate ; ocelli wanting ; wings with few 

 nerves, carried flat on the back, or roof-like, 

 when at rest; legs long, not armed with 

 spines. Deposit their eggs in leaves and 

 stems ; producing galls. 



