410 CLASS VIII. ORDER XIle 
Asiuus,’ (hornet-fly,) mouth with a straight, 
horny, bivalve snout. . 
Empis, mouth with a horny, inflected, bivalve 
snout, longer than the thorax, with horizontal 
valves. 
Bompy.tius, (humming-fly,) mouth furnished 
with a very long porrected, setaceous, bivalve 
trunk ; with horizontal valves including setace- 
ous piercers. i 
Tasanus, (ox-fly,) mouth formed into a fleshy 
proboscis, terminated by 2 lips; rostrum furnished 
with 2 pointed palpi, placed on the side of, and 
parallel to, the proboscis. 
Conoprs, mouth with a porrected, jointed snout. 
Orsrrus, (gad-fly,) antennz triarticulate, very 
short, sunk; face broad, depressed, vesicular ; 
mouth a simple orifice ; feelers 2, biarticulate, 
sunk ; tail inflected. 
Musca, (house fly,) mouth formed into a fleshy 
proboscis, with 2 lateral lips ; palpi none. 
Diopsis, (stem-eye,) antennz very small, seta- 
ceous, eyes situated on very long footstalks. 
Hurrogosca, (horse-fly,) mouth furnished with 
a bivalve, cylindric, obtuse, natant snout; bedy | 
depressed ; feet furnished with several claws, 
