460 INSECT A. 



worms without feet, thickest and truncated at the posterior extremity, and 

 becoming gradually smaller towards the opposite one, which terminates in a 

 point furnished with two hooks, with which they divide their aliment, and 

 accelerate its decomposition. The metamorphosis of these insects is effected 

 in a few days. The posterior extremity of the abdomen of the females is 

 narrowed and prolonged in the manner of a tube or ovipositor, by which she 

 can insert her eggs. 



M. vomitoria, Lin. A large species ; front fulvous ; thorax black ; abdomen 

 glossy-blue with black streaks. 



This insect enjoys the sense of smell to a high degree, announces its pre- 

 sence in our dwellings by a loud humming, and deposits its ova on meat 

 Deceived by the cadaverous odour arising from the Arum dracunculus, Lin., 

 when in flower, it also leaves its eggs there. When the larva is about to 

 become a pupa, it abandons the putrescent matters in which it has lived, 

 which might then prove injurious to it, and penetrates, if possible, into the 

 earth, or is metamorphosed in some dry and retired spot. 



M. CcEsar, Lin. Body, a glossy golden-green; legs black. The female 

 deposits her eggs on carrion. 



M. domestica, Lin. The thorax of the common fly is of a cinereous-grey 

 with four black streaks; abdomen blackish-brown spotted with black, and 

 yellowish-brown above. 



In the Diptera of which we have hitherto spoken, we have found a sucker 

 received into the superior canal of a tubular sheath, more or less membranous, 

 geniculate at base, most frequently terminated by two lips, and accompanied 

 by palpi. The antennae, except one subgenus or Phora, have always appeared 

 to be inserted near the front. The larvae of these Diptera, although susceptible 

 of being hatched in the venter of the mother, live abroad and feed on various 

 substances, vegetable or animal. These insects have formed our first general 

 section, which is divided into five families. Those of the second differ in all 

 these respects. 



This second section will form our last family of the Diptera. 



FAMILY VI. 



PUPIPARA*. 



THESE insects, at least the Hippoboscte, were distinguished by Reaumur, 

 under the analogous appellation of Nymphipara. 



Their head, viewed from above, is divided into two distinct area- or parts. 

 One posterior, and more particularly composing the head, gives origin to the 

 eyes and receives the other part in an anterior emargination. The latter is 

 also divided into two portions, the posterior large and coriaceous, bearing the 



Born'in the pupa state. 



