MANUAL OF NATURAL HISTORY. 253 



3. Family. — Sand-Flies (Bibionidae). Antennae sel- 



dom longer than head, thick, cylindric, moni- 

 liform or perfoliate ; wings large ; ocelli two 

 or three ; pronotum conspicuous ; palpi 4- 

 jointed ; eyes, in males, large, contiguous. 

 Found in marshy places ; yery troublesome to 

 man and domestic animals. 



4. Family. — Black-Flies (Simuliidae), Antennae 



seldom longer than head, cylindric or moni- 

 liform; ocelli none; wings and halteres large; 

 costal vein ending near tip of wing; tibiae 

 and metatarsi broad, compressed. Found in 

 damp marshy places ; sometimes termed 

 "Mosquitoes"; obnoxious to man and beast. 



5. Family. — Midges (Chironomidae). Antennae slen- 



der, filiform, beset with long hairs forming in 

 the males a large plume or brush, longer 

 than head, basal joint very large ; ocelli ob- 

 solete ; eyes lunate, separate ; body long and 

 slender ; legs very long, tibiae simple, not 

 armed with spines ; often assemble in cloud- 

 like swarms, and perform aerial dances. 



6. Family. — True-Gnats (Culicidae). Antennae slen- 



der, filiform, plumose ; basal joint sub-globose, 

 tubercular ; palpi very long, pilose at end ; 

 head small ; mouth produced into a long 

 slender rostrum ; ocelli obsolete ; eyes lunate ; 

 body long and slender ; wings oblong, round- 

 ed at tip, incumbent, hind margins fringed 

 with scales. Produce irritating bites ; species 

 constitute the true " Mosquitoes." 



