[Illustration: Fig. 22. Ox Warble-fly (_Hypoderma bovis_), _a_, female; _b_, full-grown maggot from back of ox, dorsal view; _c_, egg; _d_, empty puparium, ventral view; _e_, young maggot from gullet, ventral view. Magnified (lines show natural size). _a-d_, after Theobald, _2nd Report Econ. Zool._ (_Brit. Mus._).]