90 



NATURAL HISTORY OF INSECTS. 



is stout and hairy, and the middle of the face is generally very 

 narrow. The larva? live in the bodies of various animals, and 

 enter the earth to change to pupae ; the pupae are coarctate. 

 The female flies are usually oviparous, but one species, the 

 Sheep Bot-fly (Fig. 233), is stated by Prof. Riley to be vivi- 

 parous. The Ox Bot-fly (Fig. 234) and the Horse Bot-fly 

 (Fig. 235) belong to this family. 



Fig. 233. 



Fig. 234. 



HOUSE-FLIES (Muscidse). These flies have the third joint 

 of the antennae furnished with a style which is either pectinate, 

 or plumose, or sometimes simple; the longitudinal veins of 

 the wings are not forked, and the proboscis usually ends in a 

 fleshy lobe. The pupae are coarctate. Fig. 236. 



Fgt. 235. 



In the Tachina-flies, the style of the antennae is simple, or, . 

 rarely, pectinate. These Flies (Fig 236) are among the most 

 beneficial of insects, since their larvae live within the bodies 

 of caterpillars, etc., ultimately causing their death. 



