650 THE WATEJl-SCOEPION. 



like the hinder wings of the same insects. In some species, however, the wings are 

 wanting, as in the common Bed-bug (Cimex lectularius). The body is always much 

 flattened, the mouth is beak-like, and in the pupal stage the creature is active and 

 resembling the perfect insect, except in its want of wings. 



Many of the species are aquatic, and are always of dull black or brown tint, while 

 the terrestrial species, and especially those of tropical climates, glow with all the colours 

 of the rainbow. The greater number of the Heteroptera feed on vegetable substances ; 

 but there are many which are predaceous, feeding not only upon other insects, but killing 

 those of their own kind. England possesses many examples of both the terrestrial and the 

 aquatic Heteroptera, and it is remarkable that almost every terrestrial species is capable 

 of emitting a very powerful odour, in most cases extremely unpleasant, but in others 

 rather agreeable. This odour is usually evolved when the creature is touched or otherwise 

 alarmed, and is evidently under the control of the insect. 



As the space which can be devoted to the remaining insects is extremely limited, it 

 will be merely possible to give a brief sketch of the different families. 



In the first section of the Heteroptera, the species are aquatic and predaceous, some 

 being very quick and active in the water, and others slow, but yet fierce and voracious, 

 and obtaining by craft the prey which the others win by fair chase. 



The first family of the Nbtonectidae, or Back-swimmers, is represented in England 

 by many species, of which the common Water Boatman (Notonecta glaucus) is the 

 commonest. These insects are in the habit of lying on the back and propelling them- 

 selves by means of the hind legs, which are very long, and with the extremities expanded 

 and fringed with stiff hairs so as to resemble and do the duty of oars. When lying on 

 the back, the insect is wonderfully boat-like, the general shape much resembling an 

 Indian canoe. These creatures breathe atmospheric air, for which they are forced oc- 

 casionally to come to the surface, receiving it under their wings, just as is the case with 

 the water-beetles already described. When the air has been taken in it is prevented from 

 escaping by means of the stiff hairs with which the segments are furnished. Any one 

 who has watched a pond in the summer-time must have noticed the Water Boatmen 

 coming to the surface, poking their tails out of the water, and then descending. The 

 beak of all this family is very sharp and strong, especially in the genus Corixa ; and a 

 heedless captor will often find a sudden pang shoot through his fingers, caused by the 

 determined thrust of the insect's sharp beak, which is armed with a pair of spear-like 

 points, the edges of which are deeply jagged. The wings of the Water Boatman are large 

 and handsome, and the insects are powerful on the wing. They fly by night. 



THE family of the Nepidse . is represented in England by the common WATER 

 SCOKHON, a very flat and leaf-like insect, which is found abundantly in slow running 

 streams, ditches, and ponds. It derives its popular name from its scorpion-like aspect, 

 the two slender filaments appended to the abdomen representing the sting-tipped tail, 

 and the raptorial fore-legs resembling the claws. It is with these legs that the Water 

 Scorpion catches its prey, which, when once grasped in that hooked extremity, is never 

 able to make its escape. The beak is short, but very strong and sharp, and is not bent 

 under the thorax as is the case with that of the water boatman. 



The two filamentous appendages of the abdomen are used for the purpose of respira- 

 tion, the air being drawn through them to the spiracles, which are situated near their base. 

 The eggs of the Nepa are very remarkable, each egg being furnished with a crown of 

 diverging filaments, which form a kind of cup, into which the succeeding egg is received, 

 so that the joined eggs have much the appearance of the common mare's-tail or equisetum. 

 The wings of the Nepa are large, and the insect is able to fly well. There is another 

 tolerably common species of this family found in England, the Naucoris, a smaller insect 

 than the Nepa, as good a flier, and a better swimmer, and a terrible one to use its sharp 

 beak with painful effect. Some of the tropical species are really formidable, being three 

 inches in length. 





