INSECTA. 
628 
the third joint shorter, nearly ovoid, and the fourth joint shorter, the style not terminal, but dorsal. O. Hy- 1 
poleon, Fab. 
Nemotelus, Geoff., differs from the preceding in having the proboscis long, siphon-shaped, elbowed at the 
base, and lodged in a frontal protuberance of the head, like a beak. 
In the other’s the third joint of the antennse forms, with the preceding, an ovoid or globular mass, terminated 
by a long seta. The scutellum is rarely spined. 
Chrysochlora-, Latr. {Sargus, Fab.), has the third joint of the antennae conic, and terminated by a seta. 
Sargus, Fab., has the same joint subovoid, or nearly globose, rounded, or obtuse at the tip, with the seta dorsal. 
The first joint is nearly cylindrical ; the scutellum rarely spined ; the body often elongate, green, or coppery, and 
brilliant. Musca cupraria, Linn., a very common species, the larva of which resides in cow dung, and is of an 
oval, oblong form, narrowed and pointed in front, with a scaly head furnished with two hooks. It becomes a pupa 
beneath its own skin, and without materially altering its form. 
Vappo, Latr. {Pachygaster, Meig.), differs chiefly from Sargus in the antennae being shorter, with the basal joints 
transverse. 
Our second general division of those Diptera which have a sucker received in the proboscis, y 
or sheath, and the antennte only 2- or 3-jointed, comprises those which have the proboscis ^ 
generally membranous, bilabiate, long, elbowed, and bearing two palpi implanted a little ^ 
above the elbow, and most commonly received into the oral cavity, and has only two pieces I 
in the sucker, when it is always protruded. The last joint of the antennae, always furnished ^ 
with a style or seta, has no annular division. The palpi are hidden in repose. This division 
forms 
THE FIFTH FAMILY OF THE DIPTERA,— 
The Athericera, — 
The proboscis of which is generally terminated by two large lips ; the sucker has never more than 
four, and often only two pieces. The larvae have the body very soft, contractile, annulated, narrower 
in front, with the head of a variable figure, and its external organs consisting of one or twm hooks, \ 
accompanied in some genera with fleshy lobes, and probably in all with a sort of tongue destined to ‘ 
receive the nutritive fluids. The spiracles are four in number ; two placed in the prothorax, and two 
at the extremity of the body, on scaly plates ; each of the latter is formed, in many, of three small 
spiracles close together. These larvae do not change their skins ; that which they first possess hardens, 
and becomes a kind of cocoon for the pupa. It also shortens, and assumes an oval form ; the anterior 
part, which was slenderest in the larva, thickens. We also discover in it traces of articulation, and 
often vestiges of spiracles, although they no longer serve for respiration. [The manner in which the 
transformation to the pupa state is effected, is described in the general observations on the order, and I 
need not be repeated.] 
Few of the Athericera are carnivorous in the perfect state. They are found, for the most part, on 
flowers, leaves, and sometimes on human excrement. I 
This family comprises the genera Comps, CEstrus, and the major part of that of Musca, of i 
Linnaeus. j 
We naturally commence with those species of the latter genus, which have the sucker formed of 
four pieces and not of two, as in all the other Athericera. They form a first tribe, Svrphid^. 
The proboscis is always long, membranous, elbowed near the base, terminated by two large lips, and ; 
the sucker inclosed in an upper canal ; the upper piece of the sucker is thick, and notched at the tip, 
the others are slender ; to each of the two labial ones, representing maxillae, is attached a small, 
slender palpus ; the head is hemispherical, and occupied for the most part by the eyes, especially in 
the males. Its anterior extremity is mostly produced like a muzzle, or beak, receiving the proboscis : 
when it is folded in inaction. Many species resemble Humble-bees, and others Wasps. This tribe 
comprises but a single genus, 
Syrphus, — 
A first general division of which is composed of those with the proboscis shorter than the head and thorax. 
Some of these have the front of the head produced into an eminence above the oral cavity ; at the head of 
these are placed such as have the seta of the antennae plumose ; the body short and hairy, resembling Humble-bees. 
Volucella, Geoffr., has the third joint of the antennae oblong, its outline forming a curvilinear and elongate | 
triangle. 
Musca mystacea, Linn., a very common species, the larva of which lives in the nests of Bombi, its body being 
