These handsome Sawflies are common in Europe and America, the larvae living in timber; the members of the typical Genus _Sirex_ have long cylindrical bodies rounded to the apex; the borer of the female extends beyond the tip of the abdomen. One species, _Sirex australis_, has been described from Australia by Kirby (List of Hymenoptera 1882). I have never heard of another specimen being found, and believe the type is unique. Family 4. Sawflies. TENTHREDINIDAE. These are the typical stoutly built Sawflies, with the pronotum narrow, and the thorax generally broader than the head; the abdomen sessile, and provided in the female with a beautiful saw-like instrument on the under-surface of the tip of the abdomen, with which she slits the leaves to deposit her eggs in the tissue. The larvae are caterpillar-like creatures usually furnished with three pairs of legs; they feed upon the foliage of many plants. Our species all belong to genera peculiar to Australia: Klug described several in the Berlin Magazin in 1814; Leach figured and described others in his “Zoological Miscellanies 1817”; Westwood described and figured a number in an important paper in the Proceedings of the Zoological Society 1880, others in his “Arcana Entomologica 1841”; and Kirby added to them in his List of Hymenoptera, B.M. Catalogue 1882. The Genus _Perga_ contains about 50 of our largest Sawflies, broad thickset insects, with reddish or light brown opaque wings, and short antennae forming an elongate club at the extremity. The larva is black or brown clothed with short scattered shining bristles, black head, three pairs of short stout legs, broad thorax, and abdomen tapering to a rounded tip. They feed gregariously upon the foliage of eucalypts, often stripping off all the leaves of the young bushes; they rest in the day time clustered together in a bunch of 50 or more round a branch, holding on with the legs; when disturbed they raise and rap the tip of the abdomen against the leaves, at the same time discharging a sticky yellow fluid from the mouth smelling strongly of eucalyptus extract. They are very subject to the attacks of dipterous and hymenopterous parasites, which these means of defence may keep away. When full grown they bury themselves in the soil, and form elongate, oval, parchment-like cocoons clustered together.