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 

 (Notonectidce) 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 Notonectidcs 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 



fi 



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 eases for several 

 vol. vi. — n 



K -Jtfc 



EUROPEAN CICADAS. 



1. Cicada orni; 2, C.jplebja and larva. 



