276 INSECTA. sd 
But few of the Athericera are carnivorous in their perfect 
state. 
They are generally found on trees, leayes and flowers, and 
sometimes on the feces of animals. 
This family comprises the genera Conops and G'strus of 
Linnzus, and most of the species of his genus Musca. 
We must naturally separate from the last those numerous 
species in which the sucker is composed of four pieces, and 
not of twe, asin all the other Athericera. They will form our 
first tribe, that of the SyreHID&. 
Their proboscis is always long, membranous, geniculate 
near the base, terminated by two large lips, and encloses the 
sucker in asuperior groove. The upper piece of this sucker, 
which is inserted near the elbow, is broad, arched and emar- 
ginated at its extremity; the three others are linear and 
pointed, or setaceous; to each of the two lateral ones, repre- 
senting the maxilli, is annexed a litthe membranous, narrow 
palpus, slightly widened and rounded at the end ; the inferior 
seta is analogous to the ligula. “The head is hemispherical, 
and mostly occupied by the eyes, that of the males particu- 
larly. Its anterior extremity is frequently prolonged in the 
manner of a snout or rostrum, receiving the proboscis under- 
neath when it is doubled. Several species resemble Bombi and 
other Wasps. M. Lepeletier de Saint-Fargeau has commu- 
nicated to the Academie Royale des Sciences, some curious 
observations on the unnatural coition of some of these Insects, 
or to use his own words, on their “ marriages adulterins.” 
the result of which, however, he was unable to follow. 
This tribe will comprise but the single genus 
SyRPHUS. 
- 
A first general division will consist of all those species in which 
the proboscis is shorter than the head and thorax. The snout, in 
those where it is distinct, is perpendicular and short. 
Then come Syrphide, in which the fore-part of the head, a little 
above the superior margin of the oral cavity, or near the origin of 
the snout, presents a prominence. 
