These are handsome flies of moderate size, many of which are very wasp-like in the shape of the abdomen and in general colouration; they have the proboscis prolonged but usually drawn up and hidden; the 3-jointed antennae inserted in front of the head are close together at the base, with the first joint very short. Comstock says that the larva of _Conops_ is a soft whitish 11-jointed flask-shaped grub, with a long neck and mouth armed with lips and hooks (mandibles) and two lateral elevated plates supporting the two spiracles. It was found by Lachat and Audouin living in the body of a _Bombus_. Most of the members of this family are found as parasites upon different bees and wasps; the flies deposit their eggs upon the perfect insects; the larva bores into the abdomen, feeds upon the contents, and finally pupates in the shell of the body. They are considered by most writers to be allied to the _Syrphidae_. This is a small family in regard to numbers of species, but they are widely distributed: Van der Wulp lists 14 species of the Genus _Conops_ from South Asia, including the Malay Archipelago (Cat. Described Diptera 1896), and others have since been described. _Conops pica_, described by Macquart from Australia, is found in the Mittagong district, N.S.W. It is slightly over ¼ of an inch in length; has large lance-tipped antennae standing out in front; a large head; the abdomen very slender at the base swelling out to a broadly rounded tip, giving it a striking resemblance to the small “mud-nest wasps.” This resemblance is further borne out by its general dark brown colour marked and banded with yellow, which upon the abdomen forms two broad bands, a spot on the sides, and a large rounded blotch on the extreme tip; the legs are banded, and the wings are striped in front with brown. Family 16. Fruit Flies, Leaf Mining Flies, &c. MUSCIDAE ACALYPTRATA. Under this heading Sharp places a large division of closely related flies comprising 29 families, which he treats in a very brief manner; we have a large number of interesting species in some of these families that are worthy of notice, for some of them are very serious pests to the gardener and orchardist. Sharp says: “Taken collectively, they may be defined as small flies with 3-jointed antennae (frequently looking as if only 2-jointed) bearing a bristle that is not terminally placed; frequently either destitute of squamae or hairy, these imperfectly developed so as not to cover the halteres; and possessing a comparatively simple system of neuration, the chief nervures being straight, so that consequently few cells are formed.”