Figures 2-5 illustrate the structure of one of the homoptera, Cicada atrata, a native of China.—Fig. 2. The head seen in front; a, a, the eyes; b, the three ocelli; c, c, the antennæ; d, the clypeus; e, the labrum; f, the labium, forming a sheath for the reception of g, g, the hair-like mandibles, and k, k, the hair-like maxillæ.—Fig. 3. Part of the mouth; d, the clypeus; c, the labrum; f′ f′′ f′′′, the two basal, and part of the long terminal joint of the labium.—Fig. 4. The seven-jointed antennæ—Fig. 5. Underside of the thorax and abdomen; T 1, prothorax; T 2, mesothorax; T 3, metathorax; A, abdomen.
We have already mentioned the comparative extent of the different orders, from which it appears that the one now under consideration is the fourth in the scale, nearly 25,000 species being supposed to exist. Rather more than 600 different kinds have been found in Britain; but most of these are inconspicuous insects of small size and obscure colouring.
The metamorphoses of these insects may be described as merely a series of moultings. The larvæ and pupæ are alike active, the latter distinguishable from the former only by having two small projections on the back which conceal the wings and wing-covers. The only perceptible difference in apterous species in their various stages, is that arising from size.
In proceeding to illustrate this order by a selection of a few species from the numerous tribes it contains, we shall first advert to that section which has been named,
Heteroptera,
The distinguishing marks of which it may be of advantage briefly to recapitulate in this place. The
