TABLE OF FAMILIES. 



75 



BB. CALYPTE1LK. 



Squamce well developed or of moderate size, not vestigial. Aux- 

 iliary vein alivays distinct in its whole course; first longitudinal 

 vein never very short, usually of considerable length. Males often 

 holoptic, or the front in that sex narroived. Thorax with complete 

 transverse suture; posterior callosity present. Usually flies of mod- 

 erate or considerable size, never very small. 



59. Oral opening small, the mouthparts small or vestigial; first poste- 



rior cell closed or narrowed (except Gastrophilus) . Bot flies. 



Oestridte, 344 

 Oral opening of usual size, the mouthparts not vestigial. 60 



60. Hypopleurae with a tuft of bristles; first posterior cell narrowed or 



closed. .......... 61 



Hypopleurae not with tuft of bristles; first posterior cell narrowed 

 or fully open in the margin. ...... 64 



61. Antennal bristle bare or somewhat pubescent. Tachinidae, 358 

 Antennal arista plumose or very distinctly pubescent. . 62 



62. Arista bare on the distal half; dorsum of abdomen rarely bristly 



on anterior part Sarcophagidae, 348 



Arista plumose or distinctlj' pubescent to tip. ... 63 



63. Dorsum of abdomen usually bristly on anterior part; legs usually 



long. . . Dexiidae, 352 



Abdominal segments without bristles, save more or less near the 

 tip; legs not noticeably elongated (Calliphorinae) . Muscidse, 337 



64. First posterior cell narrowed or closed; arista plumose to tip. 



Muscidse, pt. 337 



First posterior cell very slightly or not at all narrowed in the 



margin; arista plumose, pubescent or bare. Anthomyidae, 331 



AA. PUPIPARA. 



65. Wingless flies, parasitic upon bats; head folding back on the dor- 



sum of the thorax Nycteribiidae, 386 



Winged or wingless flies, parasitic upon birds or mammals; head 

 not folding back upon dorsum or thorax. 66 



66. Antennae reduced; wings with distinct parallel veins and outer 



cross-veins when present; claws simple; palpi leaf-like, project- 

 ing in front of the head; almost exclusively parasitic upon bats. 



Streblidse, 384 

 Antennae usually more elongate, the joints more or less distinctly 

 separated; head sunk into an emargination of the thorax; wings, 

 when present, with veins more or less crowded anteriorly, the 

 weaker ones running outward and backward, the cross-veins 

 short and approximated to the base of the wing; claws large, 

 bidentate or tridentate ; palpi not leaf-like nor protruding in 

 front of the head. .... Hippoboscidae, 382 



