DIPTEllA. 501 



bot-fly, altliough it comes from a miich larger maggot. The 

 sheep bot-lly ( Ccphalemyia ovis) lays its eggs in the nostrils of 

 sheep, and the maggots crawl from thence into the hollows in 

 the bones of the forehead. Deer are also adlicted by bots pe- 

 culiar to them. Our native hare, or rabbit, as it is commonly 

 called, sometimes has v.ery large bots, which live under the skin 

 of his back. The fly ( CEstrus buccatus) is as big as our largest 

 humble-bee, but is not hairy. It is of a reddish black color ; 

 the face and the sides of the hind body are covered with a 

 bluish white bloom; there are many small black dots on the 

 latter, and six or eight on the face. This fly measures seven 

 eighths of an inch, or more in length, and its wings expand 

 about three quarters of an inch. It is rarely seen ; and my 

 only specimen was taken in the month of July, many years ago. 



At the very end of this order is to be placed a remarkable 

 group of insects, which seems to connect the flies with the true 

 ticks and spiders. Some of these insects have wings; but 

 others have neither wings nor poisers. Of the winged kinds 

 there is one [Hippobosca equina) that nestles in the hair of the 

 horse; others are bird-flies {Ornithomi/ia), and live in the plu- 

 mage of almost all kinds of birds. The wingless kinds have 

 sometimes been called spider-flies, from their shape; such are 

 sheep-ticks {Mellophagus ovis), and bat-ticks {Nycteribia). 

 These singular creatures are not produced from eg^^, in the 

 usual way among insects, but are brought forth in the pupa 

 state, enclosed in the egg-shaped skin of the larva, which is 

 nearly as large as the body of the parent insect. This egg-like 

 body is soft and white at first, but soon becomes hard and 

 brown. It is notched at one end, and out of this notched part 

 the inclosed insect makes its way, when it arrives at maturity. 



The flea {Pidex), may almost be considered as a wingless 

 kind of fly. Its proboscis seems to be intermediate in its for- 

 mation between that of flies and of bugs; its antennae are 

 concealed in holes in the sides of its head, like those of certain 

 water-bugs [Nepa and Belostoma), and somewhat resemble 

 them in shape; while the transformations of the flea are not 

 very much unlike those of the flies, whose maggots cast off 

 their skins on_ becoming pupae. 

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