Most of our species have been described by Macleay (Trans. Ent. Soc. N.S.W. 1871), and Blackburn (Pro. Linn. Soc. 1888). _Hydrophilus latipalpus_ is of the usual boat-shaped form; shining black; and the wing covers are very finely marked with punctured parallel striae. It measures nearly 1½ inches, and is found about Sydney. _H. albipes_ is a much smaller beetle of similar form and colour; it is found in the Murray River districts. Family 6. Rove Beetles. STAPHYLINIDAE. These peculiar beetles can be readily distinguished from most of the other families by their abbreviated elytra, which do not protect more than a third of the abdomen leaving the hind portion quite bare; while the well developed hind wings are tucked away out of sight under them, but can be quickly extended and used for flight. The apical segments of the abdomen are very flexible, and most species have the habit of turning up the tip of the body when running along; others have the power of discharging a strong scent, in some cases with quite a pleasant odour. They are slender elongate insects with stout jaws, and the antennae thickened or clubbed at the extremities; the tarsal joints are variable in number. Rove Beetles are found in many different situations, but chiefly upon the ground in the vicinity of manure, decaying vegetable matter, dead animals, and even on the seashore hiding under stones and seaweed, though most of them only seek these places to devour other small creatures, for they are carnivorous in their habits. Some of the foreign species are found living in the nests of ants, but I do not think any with this peculiarity have been recorded from Australia. The principal writers on our Staphylinidae are Macleay (Trans. Ent. Soc. N.S.W. 1871), and Fauvel in his work on “Les Staphylinides de l’Australie et de la Polynesie” (1878). In 1886 Olliff commenced his revision of the Staphylinidae of Australia (Proc. Linn. Soc.), but this only ran into the third part and was never finished. Others have been described by Blackburn (Trans. Royal Soc. S.A. 1887). About 400 species have been recorded from this country representing most of the typical sub-families. The Genus _Aleochara_ contains a number of small short black beetles with thickened antennae; those in _Homalota_ are even smaller but more slender; several species are found under cowdung. _Quedius luridipennis_ measures over ⅓ of an inch in length; the shining black head and thorax are almost globular, the latter the larger; the broad flattened fore wings are red; the margins of the abdomen are flanged and slightly spined, and the tip fringed with three tufts of bristles.