STAPHYLINOIDEA  .—The members of this tribe may be easily recognized by their wing-nervuration .

Close to a transverse fold near the base of the wing, the median nervure divides into branches which extend to the wing-margin; there is a second transverse fold near the tip of the wing, and cross nervures are altogether wanting . There are four malpighian tubes, and all five tarsal segments are usually recognizable . With very few exceptions, the larva in this group is active and campodeiform, with cerci and elongate legs as in the Adephaga, but the leg has only four segments and one claw . punctata . Europe . (Sexton Beetle) . Europe . The Silphidae, or carrion beetles, form one of the best-known families of this group . They are rotund or elongate insects with conical front haunches, the elytra generally covering (fig . 10) the whole dorsal region of the abdomen, but sometimes leaving as many as four terga exposed (fig . II) .

Some of these beetles are brightly coloured, while others are dull

black . They are usually found in carrion, and the species of Necrophorus (fig . II) and Necrophaga are valuable scavengers from their habit of burying small vertebrate carcases which may serve as food for their larvae . At this work a number of individuals are associated together . The larvae that live underground have spiny dorsal plates, while those of the Silpha (fig . Io) and other genera that go openly about in search of food resemble wood-lice . About I000 species of Silphidae are known . Allied to the Silphidae are a number of small and obscure families, for which reference must be made to monographs of the order . Of special interest among these are the Histeridae, compact beetles (fig . 12) with very hard cuticle and somewhat abbreviated elytra, with over 2000 species, most of which live on decaying matter, and Hi.ster iv-maculatus Oxyporus rufus . Stenus biguttatus . (Mimic Beetle) .

Europe . Europe . Europe . the curious little Pselaphidae, with three-segmented tarsi, elongate palpi, and shortened abdomen; the latter are usually found in ants' nests, where they are tended by the ants, which take a sweet fluid secreted among little tufts of

hair on the beetles' bodies; these beetles, which are carried about by the ants, sometimes devour their larvae . The Trichopterygidae, with their delicate narrow fringed wings, are the smallest of all beetles, while the Platypsyllidae consist of only a single species of curious form found on the beaver . The Staphylinidae, or rove-beetles—a large family of nearly Io,000 species—may be known by their very short elytra, which cover only two of the abdominal segments, leaving the elongate hind-body with seven or eight exposed, firm terga (figs . 13, 14) . These segments are very mobile, and as the rove-beetles run along they often curl the abdomen upwards and forwards like the tail of a scorpion . The Staphylinid larvae are typically campodeiform . Beetles and larvae are frequently carnivorous in habit, hunting for small insects under stones, or pursuing the soft-skinned grubs ofbeetles and flies that bore in woody stems or succulent roots . Many Staphylinidae are constant inmates of ants' nests .