RHYNCHOTA ; HOMOPTERA. 185 



They are composed of the nerves alone, without any intervening 

 membrane ; this last seeming to have been transformed into 

 the fringe. The Plumed Moths are of small size ; some of them 

 are diurnal and brightly-coloured ; others are twilight-fliers, 

 and of a duller aspect. Some species have the power of folding 

 up the wings like a fan ; so that, when closed, they present the 

 appearance of a single broad ray. 



ORDER VII. RHYNCHOTA. 



780. The Insects of this Order, which correspond with the 

 Hemiptera of Latreille, present many curious anomalies both in 

 structure and habit. It is in the construction of the mouth that 

 there is the greatest agreement ; this is adapted for suction, the 

 lower lip being elongated, jointed, and channeled like a gutter, 

 inclosing four bristle-like organs, which are the representatives 

 of the mandibles and maxillae ( 673). Their food consists of 

 the juices of animals and plants, the majority deriving their 

 nourishment 1'roin the latter source. Their metamorphosis is 

 incomplete. Their differences of organisation may be referred 

 to two principal types, by which means the order is divided into 

 two sub-orders : these are, I., the HOMOPTERA, with the anterior 

 wings of the same consistence (either membranous or leathery) 

 throughout, and the mouth directed backwards, so that the ros- 

 trum originates from the posterior part of the head ; and II., 

 the HETEROPTERA, in which the anterior wings are distinctly 

 divided into two portions, the basal horny, and the apical mem- 

 branous ; and the rostrum springs from the anterior margin of 

 the head. 



781. Sub-order I. HOMOPTERA. All the Insects of this 

 group subsist on vegetable juices ; and some of them, from the 

 amount of damage they commit, are very injurious to the culti- 

 vator. Some of the females are furnished with an ovipositor, 

 provided with several toothed saws ; and with this they make 



