60 THE DIPTERA-BRACHYCERA OP TASMANIA, 



be discovered. The Australian species have the scutellum 

 armed, in this respect differing from all the Palsearctic and 

 from most of the American species. 



10. AcANTHASAEGUS, Gen. nov. 

 Black flies with a two-spined scutellum ; antennae with a 

 loner subterminal arista; abdomen flattened, increasing 

 gradually in breadth from the base to the penultimate 

 segment. 



Fig. 6. Wing of Acanthasargus palustris. 



Heai wider thiin the front part of tlie thorax', excavated 

 behind, and attached to the prothorax by a slender neck. 

 Face considerably produced. Eyes bare. Antennae placed 

 rather below the middle of the head, short and thick, the 

 third joint annulated and provided with a long subterminal 

 arista. Thorax long ; tiie scutellum armed with two slender 

 spines, which rise obliquely from the scutellum at tm angle 

 of al>out 45 degrees. Abdomen with base much narrower 

 than the thorax, but gradually widening until the last seg- 

 ment, where it again contracts, tlie greatest width being 

 slightly greater than the greatest width of the thorax. 

 Wings with the costal vein barely extended beyond the tip 

 of the cubital; cubital vein forked ; praefurca (common stem 

 of the radial and cubital veins) lias Mie discal cross-vein close 

 to its base; both the discal and the lower cross-veins are 

 very short; the three veins from the discal cell, as well as 

 the upper branch of the postical vein, are incomplete, and 

 do not nearly reach the wing margin ; anal cell closed at 

 some distance from the wing margin. 



This genus resembles Raphiocera (South and Central 

 America and New Caledonia) in having an armed scutellum 

 and forked cubital vein, but the shape of tlie abdomen and 

 uniform black colouration at once distinguish it. It is 

 represented by one Tasmauian and one or two Victorian 

 species, none of which have so far been described ; all seem 

 to be of considerable rarity. 



Acanthasargus palustris, Sp. nov. (Fig. 6.) 

 Thorax and abdomen black ; scutellum with two black 

 spines ; legs yellow. 



Length. Female, 5.5 mm. 

 Hab. Mangalore. 



