NOUTII AmEIUCAN Dil'TKUA. 66 



1. Front entirely without bristles. .... Gymnophoua 

 Front with long bristles. 2 



*2. Middle tibiiv beset with bristles along the outer side. Trinkuua 

 Middle tibi.-e with a few or no bristles on the outer side. Phoua 



'I'kinkuka Meigen, Illiger's Magaz. 1803. 

 (ivMNOi'iioitA Macquart, Hist. Nat. Dipt. 1835. 

 Phoka Latreille, Hist. Nat. des Crust, etc. 1804. 



HIPP( )BOSCIDiE. 



Head depressed, flattened, closely attached to the eniarginate 

 thorax. Antenni? inserted in depression near the oral margin, ap- 

 parently one-jointed, with a terminal bristle or style. Face short. 

 Kyes small ; ocelli present or absent. Thorax depressed, flattened, 

 leathery, with a well-marked transverse suture. Scutellum broad 

 and short. Abdomen oval, flattened, horny above. Legs short and 

 strong, broadly separated by the sternum, the femora dilated; tarsi 

 short and broad, the first joint of tiie four anterior, or of all, abbre- 

 viated ; claws strong and well developed, often toothed below. 

 Wings sometimes absent; when present, with variable neuration, 

 the veins on the front part usually strong, and those posteriorly 

 weak. 



The flies are parasitic in their adult stage upon mammals and 

 birds; the immature stages are completed within the body of the 

 femstle, the large puparium being extruded only a little before the 

 time for the mature fly to emerge. 



1. Wings wholly wanting Melophaodb 



Wings present, functional, or rudimentary. ... 2 



2. Claws below with three teeth ; ocelli present. Ornithomyia 

 Claws with two teeth ; ocelli usually wanting. ... 3 



3. Wings rudimentary, or, if present, with weak and indistinct 



veins. Lipoftena 



Wings large, the veins in front strong 4 



4. The furcation of the second and third veins at or beyond the 



middle of the wing • Hippobosca 



The furcation of the second and third veins takes place near the 

 base of the wing. . Olfersia 



Olkkksia Wiedemann, Auss. Zweifl. Ins. II, 1830. 



