38 THE DIPTERA-BRACHYCERA OF TASMANIA, 



4. Abdomen broad ; antennse with third joint auniilated. 



TABANID^. 

 Abdomen narrow, and antennae rarely annulated. 



LEPTIDvE. 

 Veins of wing run parallel with the hind margin. 



NEMESTRINID^. 

 Head minute, abdomen inflated, squamae very large. 



CYRTID^. 



5. Wings with only three or four posterior cells. 



BOMBYLIDiE. 

 Wings with five posterior cells. 6 



6. Front excavated between the eyes, and attached to 



the thorax by a slender neck. ASILIDJE. Front not 

 excavated between the eves, and set close against 

 the thorax. ' THEREVIDiE. 



7. Antennae with arista very long and thread-like ; all 



basal cells very short. DOLICHOPODIDiE. 



Antennae without a very long and thread-like arista; 

 first and second basal cells not very short. EMPIDiE. 

 Wings, with two strong anterior veins^ reachmg only 

 half-way to the tip, and three or four faint veins 

 running diagonally across the wing. PHORIDiE. 



Family I. LEPTIDiE. 



Bristleless flies of elongated shape, having the squamee 

 small, and the posterior tibiae spurred. 



Head semi-circular, usually very short, and flattened 

 above ; face short, the antennse being placed near the mouth ; 

 the antennae of various shapes, but only annulated in the 

 small sub-families Xylophagme and Gamomyine, the latter 

 unrepresented in Australasia. Thorax normal in shape. 

 Abdomen, with seven obvious segments beside the genitalia. 

 Legs usually rather long, without any strong bristles ; hind 

 tibiae always spurred, the front and middle tibiae usually so. 

 Wings with a normal venation; the discal cross-vein is 

 placed near the base, or at least on the basal third, of the 

 discal cell ; fourth posterior cell usually wide open ; stigma 

 generally well defined. 



This family, so far as is known at present, is represented 

 in Tasmania by six species, four of which are now described 

 for the first time. 



The species seem to be somewhat local, but where they 

 occur at all, they usually do so in considerable numbers. 

 Their habits are very various. One species is blood-sucking ; 

 the others may be found settled on vegetation, on the stones 



