136 SCHOOL ENTOMOLOGY 



other large flies, the Midas-flies (Midaidce), which are, 

 however, less numerous in species and individuals. 



87. The Horse-flies. Tabanidce. The mosquito form 

 and its modifications may be taken as the type of one 

 group of fly families. The other type is represented by 

 the horse-flies. They have broad, short and rather flat 

 bodies and short legs. They are medium to large in size 

 and have exceedingly powerful flight. They may often- 

 times be noticed circling easily around a horse in full 

 gallop. While few definite characters other than those of 

 wing venation can be cited to identify the horse flies, it 

 may still be noted that they give the impression of having 

 firm bodies of regular outline, the abdomens taper usually to a 

 blunt but definite point, and the hind angles of the large com- 

 pound eyes are usually slightly produced backward forming 

 an angle and giving the hind margin of the head a strongly 

 concave shape. The larvae live in wet soil or in the water. 



Many species are annoying to horses * and cattle and 

 even to man. Some are called Ear-flies, some Gad-flies, 

 this name being applied also to some of the bot-flies, 

 mentioned later, and one small species with banded wings 

 is called the Shad-fly, or the Deer-fly, and frequently an- 

 noys man in low, wooded regions near the water. 



88. The Black-flies, so-called (Simuliidce) , are inter- 

 mediate in form between the mosquito-like type and the 

 house-fly type, having fairly slender bodies and short 

 legs. The family includes several species which attack 

 man and may be very annoying, and also some species 

 that attack domestic animals and poultry. The Buffalo- 

 gnat and the Turkey-gnat, both well known in the South 

 in the regions which they infest, are examples of forms 

 having the latter habit. They inflict severe losses in the 



* See page 200, Part II. 



