The Genus _Miltogramma_ comprises a number of smaller flies common in Europe, which lay their eggs upon the captured prey of the sand wasps while the latter are placing them in their burrows in the ground; and not only does the parasitic fly larva devour the food supply, but also when that is finished, feeds on the baby wasp. An Indian species is parasitic upon one of the large plague locusts. I have a very handsome undetermined species from Southern Queensland which has the abdomen ringed with bright yellow bands; this would suggest that it may deposit its eggs in the underground chambers of a similarly banded _Bembex_. Another much smaller species, not unlike the house fly in size and general colouration, has the grey abdomen barred with black. Family 19. Metallic Green Flies. DEXIIDAE. These flies differ from the Tachinidae, which they otherwise resemble, in having longer legs, and the bristle of the antennae pubescent or plumose. Australia is rich in large handsome species, often brightly marked with metallic tints; they are usually most plentiful in open forest country, often resting on tree trunks; when flying round they make a loud humming sound. Most of them are parasitic in their habits, depositing their eggs upon the larvae of lamellicorn beetles that are buried in the ground. _Chaetogaster violacea_ is of the usual thickset form, with a broad body and long pointed wings; it measures nearly 1 inch from the front of the head to the tips of the folded wings. It is of a general dark metallic blue colour, with the dorsal surface of the head and thorax marked with grey, and the whole insect is clothed with scattered black bristles. The wings are clouded with dull yellow on the basal half, giving it a very distinctive appearance. _Amphibolia fulvipes_ is another very handsome and smaller fly with a broader body than the last, but the wings are shorter and clouded at the base; the head and legs are yellow; the rest black, with the thorax spotted behind and marked with a row of short broken parallel bars in front; the greater part of the abdomen above and below is creamy white mottled with seven bilobed blotches of black forming a pattern on the dorsal surface. It is found about Sydney and has a wide range on the eastern coast. _Amenia leonina_ is about ½ an inch in length with a more rounded abdomen. The large head is bright yellow, with the thorax and abdomen rich metallic blue; the sides of the thorax and abdomen are marked with several white circular dots, the last two on the tip of the abdomen very distinct. It is found in Tasmania, and ranges along the eastern coast of the mainland into Queensland.