264 



The Orders of Insects 



the third. This is a character of the brachycerous Orthorrhapha, but 

 the form of the hind-body, narrow at the base and broadly conical 

 behind, in conjunction with the very broad head, separates them from 

 all the families of that group. 



CEstridae- — The (Estridi^ or Bot-flies may be distinguished from 

 the preceding families of the Gyclorrhapha by having the anal cell of 

 the wings short, confined by a cross-nervule to a small pait of the 

 basal area. They are hairy, bee-like flies with comparatively small 



Fig. 146. — House-fly {Musca dontestica, Linn.), Europe, etc. a. Male ; d. head 

 of female ; e. puparium, magnified 9 times ; c. 2nd and 3rd segments of 

 feeler ; b. maxillae (proboscis) and palps, more highly magnified. From 

 Howard, Bull. 4 (n.s.), Div. Ent. U.S. Dept. Agr. 



eyes, and with the jaws and their palps reduced to a vestigial con- 

 dition. The hind-body has six visible segments ; the female has a 

 long tubular ovipositor composed of the hinder segments. The 

 larvje are stout, barrel-shaped, tough-skinned maggots armed with 

 numerous spines; they live parasitically in the bodies of mammals in 

 which the female lays her eggs. Some species inhabit the nasal 

 cavities, others the food-canal, others, like the warble-fly {Hypoderma 



