268 CLASSIFICATION OF INSECTS. 



themselves to the bark and leaves of trees, on which they 

 deposit their eggs, covering them with their bodies. Coccus. 



Plant-lice or Aphites. Antenna conspicuous, elongate, 

 seven-jointed ; fore wings deflexed, meeting over the back 

 with a straight suture; hind wings much smaller and shorter;' 

 all the wings membranaceous; legs of uniform structure, 

 not formed for leaping; tarsi two-jointed. Infest all vege- 

 tables, sucking the sap : reproduction without union of 

 sexes for many generations. Aphis. 



Moth-blights or Aleyrodites. Larva oval, flat and scale- 

 like. Pupa changes within the skin of the larva ; is quies- 

 cent. ImagovdXh the antenna filiform, conspicuous and six- 

 jointed ; wings equally developed, both as to length and 

 breadth, covered with a white, mealy substance, like the 

 scales oi Lepidoptera ; legs of uniform structure, not formed 

 for leaping. Sits on the under-side of the leaves of the 

 plants on which the larva feeds. Aleyrodes. 



Neuroptera. — The metamorphosis of the seventh class, 

 Neuroptera, differs in its different orders. Larva with strong 

 corneous mandibles moving horizontally, and six articulate 

 feet, situated in pairs on the second, third, and fom'th seg- 

 ments; prehensile feet none. Pupa yaxiovis,. Imago us,\xdl\y 

 with the organs of the mouth perfect; the wings fully de- 

 veloped, and resembhng net-work. 



Pearl-flies or Perlites. Larva with long, filiform, multi- 

 articulate antenna ; strong, corneous, masticatory mandi- 

 bles ; teluni furnished with two long, setiform appendages ; 

 active, carnivorous, aquatic. Pupa isomorphous. Imago 

 with long, filiform, multi-articulate antenna ; strong, cor- 

 neous, masticatory mandibles ; wings fully and equally de- 

 veloped, reticulated, recumbent ; the hind wings folded ; 

 tarsi three-jointed. Inhabits the banks of running waters, 

 and is a very favourite food of fish ; flight nocturnal. Perla, 

 Isogenus, Chloroperla, Nemoura. 



