550 THE WATER-SCORPION. 



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 

 colors 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 odor, in most cases extremely 

 unpleasant, but in others rather agreeable. This odor is usually evolved when the 

 croature 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 Notonectidae, or Back-swimmers, is represented in England 

 by many species, of which the common Water Boatman (Notonecta glancus} 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. Anyone 

 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 Nepidae is represented in England by the common WATER 

 SCORPION, 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 Nau- 

 coris, a smaller insect than the Nepa, as good a flier, and a better swimmer, and a ter- 

 rible one to use its sharp beak with painful effect. Some of the tropical species are 

 really formidable, being three inches in length. 



