ORDER VIII. NEUROPTERA. —DRAGON-FLIES. 309 
remind one somewhat of the form of the insect, only their body is more 
compact and their head flattened. The larve and pupx inhabit the bottom 
of ponds and streams, where, keeping out of sight in the mud, they seek 
for insects, mollusks, small fish, &c. If any prey passes within their reach, 
they dart forwards, like a spring, a very singular arm, which represents the 
under lip. It is a sort of animated mask, armed with strong, jagged pin- 
cers, and supported by strong joints, the which, taken together, is equal to 
the body itself. This mask acts at the same time as a lip and an arm; it 
seizes the prey on its passage, and conveys it to the mouth. “When any 
insect approaches them at a time when they are in a humor for eating,” says 
Charles De Geer, “they shoot the mask forward very suddenly, and like a 
flash of lightning, and seize the insect between their two pincers; then, 
drawing back the mask, they bring the prey up to their mandibles, and 
begin to eat. I have remarked that they do not spare those of their own 
kind, but that they eat each other up when they can; and I have also seen 
them devouring very small fish which I put by them. It is very difficult 
for other insects to avoid their blows, because, walking along generally in 
the water very gently, and, as it were, with measured steps, almost in the 
same way a cat does on the lookout for birds, they suddenly dart forward 
their mask, and seize their prey instantancously.” 
The respiration of these larvw is very singular. Their abdomen is termi- 
nated by appendages, which they open to allow the water to penetrate into 
the digestive tube, whose sides are furnished with gills communicating with 
the trachexw. The water, deprived of oxygen, is then thrown out, and the 
larva advances thus in the water by the recoil. It has no tufts of external 
lateral gills, which, in the case of the Ephemerx, do the duty of fins. The 
pupa already presents stumps of wings. ‘To effect its metamorphoses, it 
drags itself out of the water, where it has lived for nearly a year, climbs 
slowly to some neighboring plant, and hangs itself there. Very soon the 
sun dries and hardens its skin, which, all of a gudden, becomes crisp, and 
eracks. The Dragon-fly then sets free its head, its thorax, and its legs ; 
its wings, still and wanting in vigor, gain strength by coming in contact 
with the air, and, after a few hours, they have attained their full develop- 
ment. Immediately the insect abandons, like a worn-out suit, the dull, 
slimy skin which had covered it so long, and which still preserves its shape, 
and dashes off in quest of prey. 
EpuemMera. — The generic name of these insects, known as May-flies, 
indicates the short duration of their life, which, in their perfectly developed 
form, is limited to a day, and often to a few hours. Their larva and pupa 
life extends through two or three years, during which they reside in the 
water, where they swim with great ease, concealing themselves at times 
NO. XIX. 92 
