328 INSECTA. 
appendages, by which they are enabled to gnaw or suck the alimen- 
tary matters on which they feed. They change their skin to undergo 
their second metamorphosis. The nymphs are naked, and exhibit 
several of the external parts of the perfect Insect, which issues from 
its exuvie, through a slit in the back. 
In our first division we find species whose proboscis, always en- 
tirely (or nearly) salient, with the exterior envelope or the sheath of 
the sucker solid or almost corneous, projects more or less in the form 
of a tube or siphon, sometimes cylindrical or conical, and sometimes 
filiform, and terminates without any remarkable enlargement, the 
lips being smal] or confounded with the sheath. The palpi are small. 
Some, that are rapacious, have an oblong body, the thorax nar- 
rowed before, and the wings incumbent; their proboscis is most com- 
monly short or but slightly elongated, and forms a sort of rostrum. 
The antenne are always approximated, and the palpi apparent. 
Astitus, Lin., 
Where the proboscis is directed forwards. 
They fly with a humming noise, are carnivorous, voracious, and 
according to their size and power, seize on Flies, Tipule, Bombi, or 
Coleopterse, which they then exhaust by suction. Their larvae have 
a small squamous head, armed with two movable hooks, live in the 
earth, and there become nymphs, whose thorax is furnished with den- 
tated hooks, and the abdomen with small spines. 
In some—Asilict, Lat.—the head is transverse; the eyes are late- 
ral and distant, even in the males, and the proboscis is at least as 
long as the head. The wings have a complete cubital cell, forming 
an elongated triangle near “the internal margin—the last of all— 
and terminating at the posterior edge. The epistoma is always 
bearded. 
Sometimes the tarsi terminate by two hooks, with as many inter- 
mediate pellets. 
Here, the terminal stilet of the antennz is but slightly apparent, 
or when it is very distinct, its second and last joint is not prolonged 
in the form of a seta. 
‘There are some of these in which the antenne are hardly longer 
than the head; their stilet is barely visible or very short, conical and 
pointed; the part of the head from which they arise is not promi- 
nent, or but slightly so. 
Lapuria, Meig., Fab., 
Where the stilet of the last joint of the antenne, which is either 
fusiform ur resembles a small obtuse head, is not (or barely) visible 
and where the proboscis is straight *. 
* See Lat., Gen. Crust. et Insect, IV, 298; Meig., Fab., Wied., and Macq. 
