CLASSIFICATION OF INSECTS 329 



// ,4. Adults usually ectoparasitic upon warm-blooded vertebrates; abdomen 



indistinctly segmented. Larvae born when about to pupate. PUPIPARA 



B. Winged or wingless flies ; eyes faceted ; palpi forming a sheath for 



the proboscis ; veins of the wing, when present, crowded anteriorly, the 



weaker veins running obliquely across the wing. Parasitic upon birds 



and mammals. Louse-flies . HIPPOBOSCIDAE 



BB. Winged or wingless ; when present the wings are pubescent, with 



parallel veins and outer cross-veins; eyes usually unfaceted; ocelli 



wanting ; antennae 2-jointed ; palpi broad, not forming a sheath for 



the proboscis. Usually parasitic upon bats .... STREBLIDAE 



C. Wingless ; halteres present ; eyes vestigial ; head folding back on 



the dorsum of the thorax. Small, spiderlike flies ; parasitic upon 



bats. Bat-ticks NYCTERIBIIDAE 



CC. Wingless; halteres 'absent; eyes vestigial; last joint of the tarsi 

 with a pair of comblike appendages. Parasitic upon the honey- 

 bee. Bee-louse BRAULIDAE 



