LJX. FAMILY HIPPOBOSCID^. 



Fig. 159. Pseudolfersiafumipennis, enlarged. After Lugger. 



Head flattened, usually attached to an emargination of 

 the thorax; face short; palpi forming a sheath for the 

 proboscis, not projecting in front of the head; anten- 

 nae inserted in pits or depressions near the border of the 

 mouth, apparently one-jointed, with or without a ter- 

 minal bristle or long hairs. Eyes round or oval, 

 ocelli present or absent. Thorax flattened, leath- 

 ery in appearance; scutellum broad and short. Halteres 

 small or rudimentary. Abdomen sac-like, leathery in 

 appearance, the sutures indistinct. Legs short and strong, 

 broadly separated by the sternum; tarsi short; claws 

 strong and often denticulated. Wings present or absent; 

 the veins always approximated to the anterior border, 

 with less strong ones running obliquely across the wing. 



The flies of this family are always parasitic in the adult 

 condition upon birds and mammals ; they have a pecu- 



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