BY ARTHUR WHITE. 63 



tisually, bearing a jointed arista. Thorax longer than broad, 

 •with dense pubescence but no bristles. Abdomen either very- 

 short and broad or fairly long and conical. Legs slender and 

 absolutely without bristles. Wings with a peculiar venation, 

 the veins towards the tip running parallel, and ending in the 

 wing margin, whilst the basal part of the cubital vein appears 

 to be carried in the form of a diagonal vein across the 

 anterior portion of the wing 



This family has its headquarters in South America and 

 the mainland of Australia. In Tasmania two genera, Exere- 

 toiieura and Tricophthalma, occur. The former genus, which 

 is confined to Tasmania, and contains only a single species, 

 is extremelv aberrant ; it may be recognised by the annulated 

 antennae, short proboscis, and spotted wings with a very 

 peculiar venation (see Fig. 8). Tricophthalma has a normal 

 venation (Fig. 9) and the proboscis is considerably lengthened; 

 of this genus four Tasmanian species have been described, 

 but these seem to be all varieties of the same species. There 

 are, therefore, so far as is known at present, only two species 

 of the Nemestrmidce occurring in Tasmania. 



12. ExERETONEURA, Macq. 

 This is an extremely interesting genus, owing to the fact 

 that it has no near allies in any part of the world. It differs 

 very much both as regards the antennae and venation from all 

 other genera of the Nemestrinido}. The annulated antennae 

 and spurred tibiae seem to indicate affinities with the Tabanidce, 

 but the form of the ovipositor in the female agrees with that 

 of the normal Nemestrhddce. The venation of the wings 

 alone is sufficient to distinguish it from every other dipterous 

 genus. 



Fig. 8. Wing of Exereto7ieura maculipennis. 



Head as broad as the thorax. Eyes bare, widely sepai-ated 

 in both sexes. Proboscis short, and barely protruding from 

 the oral aperture. Antennae with the first joint about three 

 times the length of the second, the third as long as the first 

 and second together, swollen and annulated. Thorax with 

 soft pubescence. Abdomen flattened, nearly parallel-sided, 

 and, in the female, produced into a long segmented ovipositor, 



