Nerve-winged Insects; Scorpion-flies; Caddis-flies 231 
verge of a deep pit (Fig. 320). The loose sand of the pit’s edge slips in and 
down, and the frantic struggles of the unlucky forager only accelerate the 
tiny avalanche of loose soil and sand that carries it down the treacherous 
slope. Projecting from the very bottom of the pit is a pair of long, sickle¬ 
like, sharp-pointed jaws, adapted most effectively for the swift and sure 
grasping and piercing and blood-letting of the trapped victims. The body 
of the ant-lion (Fig. 319) is almost wholly concealed underneath the sand; 
only the vicious head and jaws protrude above the surface in the pit’s depths. 
Comstock has seen the ant-lion throw sand up from the bottom, using its 
flat head like a shovel in such a way that the flung sand in falling would 
strike an ant slipping on the slope and tend to knock it down the side. Ant- 
lion pits are to be found all over the country, in warm, dry, sandy places. 
The ant-lions can be brought home alive, and kept in a dish of sand, where 
their habits may be observed. 
The adult ant-lion (Fig. 321) is a rather large, slender-bodied insect 
with four long oar-shaped gauzy wings, thickly cross-veined and usually 
more or less spotted with brownish or black. The eggs are laid in the sand 
Fig. 321. —Adult ant-lion, Myrmeleon. (Natural size.) 
and the freshly-hatched larvae or ant-lions immediately dig little pits. When 
the larvae are full-grown—and just how long this takes is not accurately 
known—each forms a curious protecting hollow ball of sand held together 
by silken threads, lines it inside smoothly with silk, and pupates in this cozy 
and safe nest (Fig. 320). The larva is said to lie for some time, even through 
a whole winter, in this cocoon before pupating. The life-history of no ant- 
lion species is yet thoroughly known. 
The family Myrmeleonidae includes eight genera, which are usually 
grouped into two subfamilies as follows: 
Antennae nearly as long as wings.... Ascalaphin^e. 
Antennae not one-third as long as wings.. Myrmeleonin^e. 
The subfamily Myrmeleoninse includes the true ant-lions with habits 
in general as already described. The five genera in it may be distinguished 
by the following key: 
