RHYNCHOTA. 
193 
Certain exotic species of this family are remarkable for their great size, attain¬ 
ing in the genus Belostoma a length of over 4 inches. The water-boatmen 
(Notonectidoe ) may be recognised by the large broad head without ocelli, and the 
short thick rostrum. They have long hind-legs fringed with hairs on one side, 
which they use like oars in swimming. When the insect comes to the surface to 
breathe, it rests with these long legs, stretched out like a boatman leaning on 
his sculls. Though the name Notonectidce has reference to their mode of 
swimming on the back, this habit is not characteristic of all the species. All 
are predaceous bugs, like all the rest of the same tribe, and are found abundantly 
in stagnant waters. Two of the common species, Notonecta glauca and Corixa 
geoffroyi are figured on p. 192. 
The Homoptera present much greater variety in external form than the 
insects of the preceding group, from which they differ in the following characters. 
The beak arises from the lower and hinder part of the head, and is, therefore, 
almost completely hidden from view. The fore-wings are, when present, of the 
same texture throughout the whole of their extent, and, in many cases, placed 
slanting, like the 
sides of a roof, when 
at rest. All the 
members of the 
section live by 
sucking the juices 
of plants ; the 
females being often 
provided with a 
horny ovipositor— 
generally composed 
of three toothed 
plates, sheathed by 
two valves—for the 
purpose of making 
incisions in plants 
where the eggs are 
deposited. Unlike 
most bugs, they are 
not odoriferous- insects, although many have special glands for the secretion of a 
kind of white waxy substance, often seen covering part of their body. The 
cicadas ( Cicadidce ) are stout-bodied insects, with a short broad head, bearing 
prominent lateral eyes, and three distinct ocelli, which are often brightly coloured 
and resemble tiny jewels set near the middle of the forehead. The short 
antennae are like small bristles inserted on the sides of the head just below the 
front margin of the eyes. The prothorax is short and broad, and the mesothorax 
also broad, on the upper side stretching back some distance behind to form a 
kind of shield. The fore-wings are longer than the hind-pair, both being often 
glossy and transparent, but sometimes finely coloured and more or less opaque. 
Cicadas remain for a long period in the larval state, in many cases for several 
VOL. vi.—13 
EUROPEAN CICADAS. 
1, Cicada orni ; 2, C. jolebja and larva. 
