168 THE DlPTKItA-BRACHYCERA OF TASMANIA, 



three joints short, the third bearing a feathered aristiform 

 style, which is quite twice the length of the three anfcennal 

 joints together. Thorax almost bare anteriorly, but with 

 long hairlike bristles posteriorly. Abdomen narrow and 

 almost parallel-sided, the sides either bare or with short 

 bristles; genitalia of male large and prominent; ovipcsito^ 

 small and not laterally compressed. Legs either long or 

 of medium length, furnished with weak bristles. Wings 

 with a normal venation ; costal margin in the male either 

 simple or inflated, and wings in both sexes sometimes rilled 

 anteriorly ; cubital fork long and embracing the wing-tip. 



Soane of the smaller species belonging to this genus are 

 difficult to identify. In cases of doubt some assistance will 

 bo alTorded by noticing the bristleo of the scutellum, which 

 in some species are only tv^^^o in number, whilst in others 

 they form a complete fringe. 



TahJe of tlie Tasmanian S/jeciss of Om matins. 



1. Wings from the middle to the tip hrown, the base 



and posterior margin hyaline. Levis, Sp. nov. 



Wings entirely hyaline. 2 



2. Legs largely reddish-yellcw ; wing;s without any 



inflation in either sex ; bare species. 



DiMiDiATus, Macq. 

 Legs black ; wings^ slightly inflated in male; hairy 

 species. Pilosus, Sp. nov. 



Ommatius DIMIDIATUS, Macq. 



Some doubt attaches to the identification of this species. 

 Miss Ricardo states that the type appears to be lost, so our 

 only means of identification is Macquart's desicription. The 

 type, a female, wasi from Tasmania. In Tasmania I have 

 not met with any specimen agreeing with Macquart's: de- 

 scription, but from New South Wales, Dr. Ferguson has 

 kindly sent me four specimens for examination which agree 

 with the description fairly well. I therefore propose to 

 describe these specimens here, under Macquart's na.me of 

 fliinidiatu'i. 



Abdomen and thorax black, with gre}^ or brown tomen- 

 tum, and whitish shoulder-spots; femora and tibije red- 

 dish-yellow, thei former with black stripes or spots above, 

 which vary greatly in extent in different specimens; wings 

 entirely hyaline, and without any sign of inflation in either 

 sex. 



Length. Male, 9 mm. ; female, 7 mm. 



Hab. Described from Tasmania, but at present only 

 known toi occur in New South Wales. 



