ODONATA, 
125 
three-jointed tarsi; as a rule there are two long anal cerci (except in 
Nemoura). They are inconspicuous insects of which apparently no¬ 
thing is yet known in India. In general the Perlidae are, in the immature 
stages, aquatic; the eggs, laid on the surface of the water, sink to the 
bottom and hatch to active nymphs ; these are flattened, with an 
elongate body, the head with biting mouthparts ; air is obtained by 
means of tufts of gill filaments ; two long many-jointed cerci terminate 
the abdomen. Those known elsewhere are predaceous, and are found 
under stones or at the bed of rapidly flowing streams. The full grown 
nymph is said to crawl out of the water before the emergence of the 
imago. The family is often classed with the order Pseudoneuroptera 
or is treated as a separate order Plecoptera. When more attention is paid 
to Neuroptera in India, they may prove to be abundant in species ; they 
are of no economic importance, direct or indirect. No species appear 
to be recorded from India. 
Odonata. — Dragon-flies. 
Two pairs of long narrow wings of equal size ; antennce very small 
and terminating in a bristle. Head large and mobile. 
Tarsi three-jointed. 
A large group of large insects, easily recognisable from nearly all other 
insects by their wings, (which are in repose held out horizontally and not 
resting over the body,) by the 
peculiar antennae, the large mobile 
head and the active habits of the 
flying insect. The imagines vary in 
length from an inch upwards with 
a span across the wings up to four 
inches. They are, as a rule, bright¬ 
ly coloured, black with blue, yellow, 
red, metallic green and other bright 
colours predominating. The colour 
is possibly warning, probably simply 
beautiful, though it is difficult 
to generalize about insects so vari¬ 
ously coloured, 
Fig’. 52— Hemioordulia asiatica. 
{From Martin.) 
