HIPPOBOSCIM. 



383 



liar louse-like appearance, and one often encounters 

 them in handling recently killed birds, especially the 

 raptorial birds. They have a quick, short flight, seek- 

 ing the beard or hair of the collector within which they 

 run nimbly, seeking to hide. The following table is 

 based chiefly upon Speiser's studies of the genera of the 

 world. 



Fig. 160. Hippoboscidae, Streblidre. I, tridentate claw; 2, Ornith- 



Oitiyia, wing; 3, Aspidoptera, wing (Speiser); 4, Trichobius, wing 



(Speiser, the slight emargination of the distal wing border is not 



shown); 5, Strebla, wing (from specimen from southern Kansas, E. 



A. Popenoe) . 



TABLE OF GENERA. 



1. Wings functional. ......... 2 



Wings vestigial or wanting. ....... 8 



2. Claws simple, that is with no accessory tooth between the enlarged 



basal plate and the tip. ....... 3 



Claws with an accessory tooth. ...... 4 



3. Three longitudinal veins present; wings caducous, often broken and 



ragged, especially in the female. . . . Lipoptena. 



Six longitudinal veins; wings not caducous. . . Ornithoica. 



4. Anal cross-vein present, the anal cell complete. ... 5 

 Anal cell open, not closed by a cross-vein. .... 6 



5. Ocelli present (2).' 



Ornithomyia, Ornithopertha, Ornithoctena. 

 Ocelli absent. . Stilbometopa. 



6. Wings lanceolate, the tip rounded; scutellum truncate. Lynchia. 

 Wings of usual shape; scutellum not truncate. ... 7 



7. Distance of oral border from frontal suture as great as from suture 



to vertex (fig. 159) Pseudolfersia. 



Distance from oral border to suture distinctly less than from sut- 

 ure to vertex Olfersia. 



8. Wings vestigial; halteres present. ...... 9 



Wings and halteres wholly wanting. . . Melophagus. 



9. Claws simple Lipoptena. 



Claws with an accessorv tooth. . Brachypteromyia. 



