THE WATER BUGS. 109 



of other insects, a predatory course of life for which the powerful typical species are particularly 

 well fitted. Many of them, when seized, will inflict a severe wound upon their captor. 



The largest British species is Reduvius personatus, an insect about three-quarters of an inch 

 long, of a blackish-brown colour, with reddish legs. It is well furnished with wings, and flies 

 especially in warm summer evenings, when it frequently enters houses, being attracted by the 

 lights. Its larva, which haunts concealed corners, disguises itself by means of a covering formed of 

 its own excrements mixed with extraneous particles, and both larva and perfect insect, when in 

 houses, are said to display a special enmity to the Bed Bug. Three or four species of the genus 

 Nabis occur in Britain on herbage, generally under the shelter of bushes. They are nearly elliptical, 

 but more narrowed in front, and generally of a brownish tint on the upper surface. The hemelytra 

 and wings are often imperfectly developed in these insects. A near ally of theirs, a very scarce 

 British species, is of a beautiful blue-black, with the hemelytra and legs bright scarlet, but the 

 former are never fully developed in northern examples. Its name is Metastemma gattula, and it 

 represents a group of Bugs, of which the typical genus is appropriately named Pirates, including 

 some of the largest and most powerful insects of this family. 



The very opposite peculiarities are presented by the Hydrometra stagnorum, which in many 

 respects leads us towards the next family. It is a slender, elongated creature, about half an inch 

 long, with the antennae and legs also exceedingly long and thin, which is found on the margins of 

 pieces of water crawling slowly about upon aquatic plants and the vegetable debris which generally 

 occur in such situations. The articulations of the legs are situated at the sides of the thoracic 

 segments, as in the Bugs of the following family, and the insect occasionally walks upon the surface 

 of the water just as they do. 



FAMILY IX. GERRID^E. 



This last family of the Geocores includes some exceedingly well-known insects, which may be 

 seen running actively over the surface of every piece of water. They have a broad head, which is 

 not contracted behind into a neck, four-jointed antennae and a three-jointed rostrum, of which the 

 second joint is the longest. The legs are inserted quite at the sides of the thorax, and the tarsi are 

 of two joints, with the claws inserted, not at the apex of the last joint, but in a notch of its 

 under side. These insects, of which several species are abundant in Britain, have boat-shaped 

 bodies, and the typical forms, such as Gcrris lacustris, which may be met with anywhere, literally 

 row themselves along the surface of the water by means of their long legs, their power of floating 

 being aided by the coating of silvery hair which covers their lower surface and carries with it 

 a portion of air. They are predaceous in their habits, feeding upon other insects. Some nearly 

 allied, but mostly very small species, with legs even longer in proportion than those of our common 

 forms, are met with at sea within the tropics, and often at a great distance from land. They form 

 two or three genera, of which the best known is Halobates. 



TRIBE II. HYDROCORES, OR WATER BUGS. 



As already stated, these insects are distinguished by the possession of very short antennae 

 concealed in pits near the eyes. The tribe includes three families, two of which are well represented 

 in Europe and Britain, while the third is exclusively American. The last-mentioned family is the 

 most nearly related to the preceding forms. 



FAMILY X.-GALGULID^. 



This family is at once distinguished from the rest of the tribe by the presence of a pair of ocelli 

 on the ci-ovvn of the head. The body is flat, and the head broad and immersed up to the eyes 

 in the thorax ; the eyes are prominent ; the antennae composed of four joints ; the rostrum three- 

 jointed, and the membrane of the hemelytra small. The legs are formed for running, and the 

 species live on the banks of rivers and lakes, where they prey upon other insects. The best-known 

 species (Galyulus oculatus}, an insect about two-fifths of an inch long, of a blackish-brown colour, 

 inhabits the southern parts of the United States. The fore legs have the femora thickened, and are 

 somewhat raptorial in character, and this peculiarity is much more strongly marked in the species of 

 Mononyx, which are found in South America, and in which the fore tarsi are represented only by a 

 sort of claw. 



