DIPTERA. 219 



ilia, sharp and wedge-shaped ; the ligula fleshy and bi- 

 lobed ; ocelli none ; wings very wide, with stout and nearly 

 parallel costal nervures ; mesothorax globose, very promi- 

 nent ; body short and small, colour black. Inhabits woods, 

 feeding on the blood of man and animals. Simulia, re- 

 presented at page 5. 



Gnats or Culicites. Larva elongate, carnivorous, active, 

 aquatic. Pupa equally active, but rather shorter, and the 

 head and prothorax much incrassated. 

 Imago with fourteen-jointed antenna, 

 plumose in the males, hairy in the fe- 

 males ; ligula slender and elongate, form- 

 ing, together with the mandibles, maxilla, 

 tongue and labrum, a porrected blood- 

 sucking apparatus ; the maxillary feelers 

 are long, divaricating, and clavate ; all the organs of the 

 mouth exceed the antennae in length ; ocelli none ; wings 

 linear, covering the body ; body narrow, linear, elongate ; 

 legs very long. Inhabits woods, &c., often entering houses : 

 feeds on the blood of man and quadrupeds. The zanque- 

 does, gallinippers, &c., of the American continents, and the 

 musquitoes of many writers belong to this order. Culex, 

 Anopheles, Chironomus, Tanypus. 



Moth gnats or Psychodites. Larva inhabits and feeds 

 on dung, putrescent fungi, &c.; elongate, subfusiform, 

 depressed, with a slender, straight, cylindrical tail, longer 

 than the preceding segment. Pupa changes in the same 

 situation ; it has two short appendages, thickened at the 

 tips, behind the head. Imago with antenna filiform and 

 perfectly simple, alike in both sexes ; ligula short, entire, 

 somewhat pointed ; wings deflexed, very hairy, enveloping 

 the body laterally, and their inner margins uniting above 

 it. Psychoda. 



Bald-headed flies or Cyrtites. Larva and pupa unknown. 



