220 DIPTEIIA. 



Family III. — Mycetophilidce. 



Small species ; antennae short or long, filiform or compressed, 

 usually sixteen -jointed, sometimes setaceous, and occasionally 

 forked ; eyes separate, generally round ; two or three ocelli present ; 

 wings with few nervures ; hind tibise sjjined ; vegetable feeders. 



The larvse of this family live gregariously in fungi, rotten wood, 

 under bark, or in similar situations. Those of the genus Sciara, 

 Meig., sometimes congregate in dense masses when full-grown, 

 which has led to their being called " Army Worms " on the Conti- 

 nent and in America, a name sometimes applied in the latter 

 country to the larva of a moth {Leucania Unipuncta, Haw.). The 

 flies are remarkable for their power of leaping. 



Family IV. — Sumdiidce. 



Small species ; antennae cylindrical, eleven-jointed ; no ocelli ; 

 first joint of the tarsi as long as all the rest together ; wings broad. 



This small family includes only the genus Simulium, Latr. It 

 is widely distributed, and some of the species are frequently called 

 Sandflies, and are exceedingly annoying both in hot and cold 

 countries by their painful bites ; they also live on honey-dew. 

 They are very restless insects, and continually vibrate their front 

 legs, which they use as feelers when at rest. 



Family V. — Bibionidce. 



Eyes of the male large and contiguous, occupying most of the 

 head ; those of the female small ; three ocelli ; prothorax large ; 

 antennse short, nine-jointed; legs and body rather short and stout. 



Several species of this group are very common, among them 

 St. Mark's Fly {Bihio Marci, Linn.), which is black, with transparent 

 wings in the male and blackish ones in the female ; and B. Hortii- 

 lanus, Linn., in which the male is black, and the female red, with 

 the head, collar, sides, scutellum, and legs black. These flies 

 appear in s})ring, and their larvae live in dung or damp earth. 



Family VI. — BlepluiriceridcB, 



Eyes of the male large, contiguous, and hairy ; in the female 

 widely separated ; three ocelli ; antennae long and slender, fourteen- 

 jointed ; wings broad and long ; legs long. 



The type of this family is Blepharicera Fasciata, Westw., a dark- 

 brown fly with transparent wings and yellow legs. It measures 

 about one-third of an inch in length. It is by no means a common 



