The typical Genus _Sarcophaga_ is world-wide in its distribution, and contains a number of well known species. _Sarcophaga aurifrons_ is our commonest species in Australia, and is also found in the Malay Archipelago. It is over ⅓ of an inch in length; the front of the head is golden; the large eyes deep red; the legs black; and the thorax and abdomen black but thickly clothed with silvery grey pubescence; the black shows through, forming three black bands on the front of the thorax; and the abdomen is mottled with indistinct spots. _S. frontalis_ is a slightly larger species with the face very bright golden yellow; the black bars on the thorax finer and darker; and the abdomen mottled with a more irregular pattern. A much smaller species, hardly larger than a house fly, was described by Skuse (Agricultural Gazette N.S.W. 1891, p. 251) as a parasite of the plague locust; he named it _Masicera pachytyli_; this fly Mr. Coquillett says belongs to the Genus _Sarcophaga_. I have since bred a much larger species from the bodies of locusts in the Bombala district, N.S.W. _Tachina oedipoda_, described by Olliff (Agr. Gaz. N.S.W. 1891, p. 769), I am also informed by Mr. Coquillett, should be _Sarcophaga oedipoda_, and is closely allied to _S. aurifrons_: it also is a parasite on the same species of locust. Family 21. House Flies. MUSCIDAE. This group comprises all the typical house flies, some of which are world-wide in their distribution. All of them have the bristle that forms the tip of the antennae hairy or plumose, while the abdomen is spineless, without bristles except at the extremity.