NEW AUSTRALIAN ASILIDjE (DIPTERA). By Arthur White. (Read 13th October, 1913.) The present paper describes seventeen new species of AsiUdcs (" Robber Flies "), eight of these being from Western Australia, and nine from Tasmania. The West Australian species were collected by Mr. G. H. Hardy, of the Tasmanian Museum, the Tasmanian species by myself. New genera are also proposed for two previously undescribed species. Leptogaster, Meig. Of this genus five Australian species have been previously described ; four new species are now added, three of these being from Tasmania, and one from Western Australia. As the species belonging to this genus are somewhat difficult to determine, I am giving a table showing the distinguishing characters of all the Australian species. Table of the Australian Species of Leptogaster. 1. Posterior legs partly or wholly black. 2 Posterior legs yellow or brown. 3 2. Abdomen black. hancrofii, Ricardo. Abdomen yellow at base. dissimih's, Ricardo. 3. Second submarginal (cubital or cubital fork) cell con-tracted at the wing margin. 4 Second submarginal cell not contracted at the wing margin. 5 4. Cross-vein closing second basal cell joins the corner of fourth posterior cell. Large species. antlpoda, Bigot. Cross-vein closing second basal cell joins peduncle of fourth posterior cell at about its middle. Small species. occidentalism Sp. nov. 5. Wings smoky. Thorax with three dark stripes ; hind femora very dark brown ; large robust species, fumipefmis, Sp. nov. Wings clear. Thorax reddish brown, with one median black strij^e ; hind femora reddish-yellow. auntralis, Ricardo. Thorax black ; hind femora brown. genicidata, Macq. Thorax brown (with three dark stripes in male) ; hind femora brown ; very small species. vertialis, Sp. nov.