350 : INSECTA. 
the pupa. It becomes shortened, assumes an ovoidal or globular 
figure, and the anterior portion, which in the larva was the narrowest, 
increases in diameter, or is sometimes even thicker than the opposite 
extremity. Traces of the annuli, and frequently vestiges of the 
stigmata are observed on it, although the latter no longer serve for 
respiration. The body is gradually detached from the skin or cocoon, 
assumes the figure of an elongated and extremely soft ball, on which 
none of its parts are perceptible, and soon passes into the state of a 
pupa. The Insect issues from its shell, by removing with its head 
the anterior extremity, which flies off like a cap, that part of the 
cocoon being so disposed as to facilitate this result. 
But few of the Athericera are carnivorous in their perfect state. 
They are generally found on trees, leaves, and flowers, and some- 
times on the feces of animals. 
This family comprises the genera Conops and Gstrus of Linnzeus, 
and most 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 two, as 
in all the other Athericera. They will form our first tribe, that of 
the SyrrHipm, 
Their proboscis is always long, membranous, geniculate near the 
base, terminated by two large lips, and encloses the sucker in a su- 
perior groove. ‘The upper piece of this sucker, which is inserted 
near the elbow, is broad, arched, and emarginated at its extremity; 
the three others are linear and pointed, or setaceous ; to each of the 
two lateral ones, representing the maxille, is-annexed a little mem- 
branous, 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 particularly. Its 
anterior extremity is frequently prolonged in the manner of a*snout 
or rostrum, receiving the proboscis underneath when it is duubled. 
Several species resemble Bombi and other Wasps. M. Lepeletier de 
Saint-Fargeau has communicated to the Academie Royale des Sci- 
ences, come curious observations on the unnatural coition of some of 
these Insects, or to use his own words, on their “ marriages adulte- 
rins,” the result of which, however, he was unable to follow. 
This tribe will comprise but the single genus 
S yRPHUus. 
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. 
