They are remarkable for their habits in the larval state, being parasitic upon the larvae and pupae of frog-hoppers, chiefly Jassidae, particularly those Homoptera that have the tip of the abdomen clothed with waxy filaments. When full grown the dipterous larvae leave their host and bury themselves in the soil, where they pupate. Mr. Koebele allowed me to examine the collection he made of these little flies before they were described by Mr. Perkins. Many of these he reared from infested frog-hoppers in Queensland when studying sugar-cane pests. _Pipunculus helluo_ was observed swarming round the larvae of _Siphanta_, which were abundant on fig trees near Bundaberg Queensland; this species was also taken by Koebele near Sydney. _P. cinerascens_ is remarkable in the larval form, as it does not fall to the ground and pupate in the soil, but forms its puparium upon the surface of the living leaves in the open. _P. cruciator_ comes from the district of Cairns, N. Queensland. Family 14. Hover Flies. SYRPHIDAE. Several species are well known and common in gardens, where they are popularly known under the name of “Bee” or “Hover Flies” from a way they have of poising, apparently motionless, over flowers and aphid-infested bushes, for the movement of their wings is so rapid as scarcely to be detected. The perfect flies, which among the carnivorous species have slender bodies more or less barred or banded with yellow, lay their eggs upon aphis-infested plants; the young larvae emerging from the white eggs feed exclusively upon aphids and plant lice; the full-grown larva is legless, very elongate in form, and has great powers for extending and contracting its abdominal segments, so that the body, from a rounded mass, can extend into a long and slender form. The full-grown larva pupates in an oval hard chrysalid which usually falls to the ground.