LIBELLULA. INSECTS. 329 



SECTION I. SUBULICORNBS. 



Antennae subulate, scarcely longer than the head, of seven joints, 

 of which the last is formed of a seta ; mandibles and jaws co- 

 vered by lips, or an anterior projection of the head ; eyes pro- 

 jecting and large ; wings extended horizontally, or in a per- 

 pendicular position. 



The insects of this section pass the first period of their life in water, and in ge- 

 neral feed on living prey. The larvae respire by means of a particular apparatus 

 placed near the anus, or by means of lateral and exterior tracheal appendages. 



FAMILY I. LIBELLULIN^:. 



Three joints in the tarsi ; mandibles and jaws corneous, very 

 strong and dentated ; wings equal ; abdomen not terminated 

 by setae or filaments ; sexual organs of the male under the 

 second abdominal ring. 



These insects are carnivorous in all their states ; fly rapidly, and during their 

 flight seize the insects upon which they feed. 



Gen. jEsHNA, (Petalura, Leach) ; LIBELLULA, AGRION. 



Gen, LIBELLULA, Lin. 



Wings extended horizontally in repose ; head almost globular ; 

 antennae short, terminated by a jointed seta ; eyes very large, 

 contiguous ; middle division of the lip much smaller than the 

 lateral ones, the three pieces joined by a suture ; abdomen 

 long, depressed, and pointed, 



The Libellulae are insects of an elegant form and beautiful colours ; but their ha- 

 bits are carnivorous, and they are not very nice in their choice of food. In their ra- 

 pid flight they seize small flies, and even the flesh-fly and butterflies ; and their ra- 

 pacity leads them into gardens, and particularly along hedge rows in pursuit of prey. 

 The larva of the Libellulae is not very different in form from the perfect insect, ex- 

 cept in the want of wings. They live for ten or eleven months in the water, and 

 change their skin many times before their transformation ; then crawling up the 

 stem of an aquatic plant when the period for their final change has arrived, the out- 

 er case splits off, and the perfect insect appears in all its beautiful colours, ready 

 to fulfil the purpose of nature in the propagation of the species. Dragon flies are 

 generally seen in pairs flying together. 



L. depressa, Lin. Yellowish brown, base of the wings blackish ; 

 two yellow lines on the thorax ; abdomen in the form of a sword 

 blade, brown or slate gray, with the sides yellowish j wings trans- 

 parent, with a large spot of yellowish brown at their base, and a 

 small oblong black spot at the end of the exterior border. 1| inch 

 long. Common in Europe. Shaw, vi. 245. 



FAMILY II. EPHEMERIN.E. 



Tarsi with four joints ; body very soft ; inferior wings much 

 smaller than the superior ones, and almost imperceptible in 

 some species ; abdomen terminated by two or three filaments. 



Gen. EPHEMERA, Lin. Lam. 



Antennae very short, terminated by a seta ; upper lip covering 

 the mouth ; mandibles none or very small ; palpi very short, 

 and indistinct ; tarsi with five joints. 



