On Woodcut XLVIII. Fig. 2, is shown another species, Hydrometra argentata.

This insect is remarkable as being the smallest of the family. Its colour is blackish-brown above, with a decided silvery gloss below. The antenna3 are black. The colour p p of the elytra is

brown in some lights and bluish-grey in others. The abdomen I of the male has the last two segments marked with a narrow ■ yellow line, and that of the female has the last four segments I similarly marked. It is much rarer than the preceding insect. I

The last of the Aurocorisa which will be mentioned in this I work is the insect wliich is represented on Woodcut LXVIII. I Pig. 4. Its name is Halticocoris luteicollis, and it belongs to I the family of Halticocoridse, or Jumping-Bugs, because they I have the capability of leaping, very much like the Halticse, or I Tui nip-fleas, which have already been described on page 211. I The structure of the hind legs, with their p-eatly developed I thighs, is sufficient to show that the insect is gifted vdth the I power of leaping. I

The general colour of this insect is shining black, over I which are spread a number of fine yellow hairs, very short, I and bent downwards. In this species the elytra are fully I developed, but in the only other British species of this genus, I Halticocoris pallidicomis, they are undeveloped. The head I and antennae are ochreous yellow, and so are the legs except I the thighs of the second and third pairs, which are black. The upper part of the thorax is very finely wrinkled in front, and has a very fine and delicate furrow running along its centre.

The insect is not a scarce one, but requires to be looked after, as it takes up its residence in clover fields, and upon several species of Bed-straw {Galium). The sweep-net will generally bring it within the reach of the entomologist.

XVIII. Fig. 4, is shown a figure of an insect called

On Plate dissimile. The insects of this genus have the Pentatoma very large, the tarsi with three joints, and the eyes scutellum In some of the family to which this insect rather prominent. is of enormous size, from which the belongs, the scutellum has derived the name of Scutellarid*. The generic family signifies ‘ five-pieces ’ or joints, and is given -name Pentatoma their antennae have five joints. Like ^ to the insects because order, they exhale a very unpleasant odour, others of the same uneatable any fruit over which they .'and sometimes render vegetable feeders, but sometimes take | orawl They are mostly

to animal food, a number of them having been observed gatliered round the body of a caterpillar, with their beaks sunk deeply into it. The well-known naturalist, De Greer, states that some species of this family watch over their eggs until they are hatched, and then take care of their young, just as is .said of the earwig. He remarked that the mother reminded him of the hen and her chickens, leading them from spot to spot, and evidently keeping guard over them until they were strong enough to shift for themselves.

Tlie same naturalist further observed that these insects can disengage the piercing portion of the proboscis from the sheath, and replace it at will. His description is as follows. I have not his work by me, but follow the translation given in Grriffith’s edition of Cuvier’s ‘ Animal Kingdom.’

‘ It has happened to me,’ says De Heer, ‘ to observe on one of these young bugs, placed under the microscope, that its proboscis was entirely disengaged out of the furrow of the sheath. It hung then at the end of the tongue, like a very long thread. I saw, again, that at the end of the thread the tluee pieces of which it was composed were separated one from the other. The following day I observed on the same bug that everything was restored to its. proper place — that the proboscis was placed, as before, in the furrow of the sheath. It appears, then, that the bug can withdraw its proboscis out of its sheath and put it back when it thinks proper. It drew the pioboscis out of its sheath once again ; I then saw how the intermediate part of the proboscis and of the point played how the bug elongated and shortened it alternately. I saw some drops of fluid come out of and re-enter the proboscis. The two semi-sheaths which accompanied it played also alternately in front and rear.

‘ I was attentive to observe how the bug caused its proboscis to re-enter into the furrow of the sheath, and at last I achieved this, after having observed it without interruption for more than a quarter of an hour. It first of all puts its proboscis in a paralKl line witli the sheath, or at least it holds it extended the entire length of the sheath ; afterwards it gives an inflexion to the sheath, about the middle of its extent. It folds it like a knee. It then applies this p p knee 2 against the middle of its

proboscis, or against that part of the proboscis which is opposite to the knee. The anterior feet then come to its assistance. The bug presses its proboscis with its feet against the sheath, so that this portion of its proboscis is then stopped in the groove or furrow. Finally, it presses the rest of its proboscis against the sheath with the same feet, and thus causes it to slide into the groove. As soon as the proboscis has once reentered, it stays there.’

CHAPTER II.

Eydeocorisa, Or Water-Bugs.

W B now come to the second group of Heteroptera — the Hydrocorisa, or Water-Bugs* There are many species, dififering greatly in external appearance ; but they all have very short antennas concealed in cavities beneatli the eyes, and their forelegs are rather short, and can be folded close to the body, so as to look like claws. With these limbs the insects seize their prey, which consists of various inhabitants of the water that do not appear to be so strong as themselves.

The first family is that of the Notonectidae, which embraces the various insects known by the popular name of Waterboatmen. The scientific name signifies Back-swimmer, and both titles are equally appropriate. The Notonectid® have a habit of lying on their backs in the water, and their body then assumes a shape very much like that of a boat. The two hind legs are exceedingly long, and as they are stretched out at right angles with the body, look exactly like oars, and indeed are used as if they were oars. The ends of these legs are furnished with hairy fringes, which act Hke the blade of the oar, and enable the insect to drive itself along with very great speed.

All who have handled an oar know of the difficulties which beset them in the proper mode of feathering, i.e. turning the oar as^ it is brought out of the water, so that the edge of the blade is turned to the air as the oar is swept backwards for the next stroke. ^ In the oar-like legs of the Water-boatman we find a provision for a similar feathering, the bristles standingout boldly as the leg is forced against the water to make the next stroke, and collapsing as the limb is drawn through the water in readiness.for the next stroke. The insect never lifts its oar-legs out of the water, and, unless some provision of the sort were made, it would travel nearly as fast backwards as

forwards. In fact, the movement of the Water-boatman’s leg very much resembles that of the North American Indian’s paddle. He never takes the paddle out of the water, but first makes his stroke with the flat of the blade, and then turns the paddle so that its edge is presented to the water as it is brought forward in readiness for the next stroke.

One of these insects, Notonecta glauca, is shown on Plate XIX. Fig. 2.

The manners and customs of the Water-boatmen are well worthy of study, and I liave passed many pleasant iiours in watching their habits, both at liberty and in captivity. As a rule, they lie on their backs in the water, but they do not always maintain this position. On fine, hot, summer days, they turn over and sit almost on the surface of the water, with the wing-cases half open and the wings partly protruding from them. In this curious attitude they will sit for an hour at a time, and even more unless disturbed, as long as the sun shines on them. It is remarkable how mere attitude will alter the aspect of an insect. The Water-boatman, as it appears when darting through the water, and when sitting sunning itself on the surface, is so totally different in aspect, that no one who was not acquainted with the insect could suspect its identity.

As is the case with aquatic insects in general, the Waterboatman breathes atmospheric air, respiration being conducted much like that of the Water Beetles, which have already been described. In the case of the Water-boatman, however, the comparative transparency of the elytra enables the mode of respiration to be seen better than can be done with the beetles. I have often watched the breathing of the Notonecta, which is conducted as follows. The insect lies on its back, with its legs spread, the tip of its tail just above the surface of the water, and its head just below it. Air is taken into the space between the elytra and the body, and is passed onwards towards the shoulders, being alternately taken in and ejected through the spiracles, and its course being traceable by the quicksilvery look which it gives to the elytra. Having completed its course througli the respiratory system, the air is sqeezed out at the junction of the elytra witli the under part

of the thorax, and ascends in bubbles to the surface. There is always a small bubble of air at that point, which continually increases in size until it is detached from the insect, rises to tlie surface, and gives way to another.

The wings of these insects are large and powerful, and can carry their owner at a considerable speed. The insect is even able to take to flight directly from the surface of the water, an accomplishment which startled me in no small degree when I first saw it. When it wishes to fly, it dives to some little distance below the sm'face, so as to bring itself into a perpendicular position, with its head upwards. It then darts upwards, giving a smart stroke with both its swimming legs as it reaches the surface. By this stroke, or leap, it is jerked several inches out of the water, when it spreads its wings suddenly, and with a loud, dull humming sound, much like that of a wasp on the wing, flies away.

In common with the rest of its kin, this is a predacious insect, feeding almost entirely upon other aquatic insects. It does not eat them, but seizes them with its fore-legs, clasps them tightly to its body, drives its beak deeply into them, and sucks out their juices, leaving their bodies scarcely altered' in form. I have often watched the Notonecta seize other inhabitants of the water, and thus kill them. When it has once clasped an insect in its fatal hold, it can scarcely be induced to lelease it until it has finished its meal, but swims about, holding its victim firmly pressed against its body until all its juices are sucked out.

It pays a great regard to its personal cleanliness, and is fond of washing itself much after the fashion of the housefly, using its fore-legs for this purpose, and passing them over every part of its body, the head being moved and twisted from side to side exactly like that of the blue-bottle under similar circumstances.

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