Dragon Flies

Dragon Flies, a number of insects comprising the order Odonata. Their main characters are the similarity of the four wings, the large powerful jaws and incomplete metamorphosis. The skin is hard and is thrown off in a succession of moults to allow of growth. They are carnivorous in all stages; the larvae and pupae are both active and aquatic; they have tracheal gills. The principal family is the Libellulidee, of which the large Libellula depressa (Linn.) is the commonest and best known of the fifty British species. The very large size of the eyes and the remarkable arrangement of the genital organs, which enables the male to fertilise the female during flight, are also features of interest. Owing to their powerful flight they are very widely distributed, one species (Pantala flavescent) being world-wide. The order is not, however, a very large one numerically: it includes about 1,700 species divided into three families. The largest species belong to the genus Mecistogaster, which has an expanse of wing of about 7 inches. The earliest known dragon flies occur in the Lias, but the best preserved ones are from the Solenhofen Slate of Bavaria (Upper Oolite).