618 



ZOOLOGY 



SECT. 



Sub-order 5. Mallophaga. 



Small, flat, wingless Orthopteroidea with very slight metamor- 

 phosis, with biting mouth-parts. 



This sub -order comprises only the Biting Lice or Bird Lice 

 (Fig. 517), which are external parasites of birds and mammals. 



ORDER 4. NEUROPTERA. 



Pterygota with two pairs of mem- 

 branous wings. The larvae live in 

 water. 



This sub -order includes the Per- 

 lidae, the Dragon-flies (Odonata), the 

 May-flies (Fig. 518), the Ant-lions 

 and the Caddis-flies. 



ORDER 5. THYSANOPTERA. 



FIG. 518. Ephemera (May-fly) and 

 larva. (After Gu&rin and Percheron.) 



slight metamor- 

 phosis, with sucking mouth-parts, 

 and usually with four narrow 

 fringed wings. 



This order comprises the insects, 

 usually of very small size, known 

 as Thrips. 



ORDER 6. HEMIPTERA (RHYNCHOTA). 



Insects in which wings are usually present, sometimes similar, 

 sometimes dissimilar, and in which there is a jointed suctorial 



v- 



FlG. 519. Aphis rosae and larva. (From Cuvier's Animal Kingdom. 



rostrum formed from the labium, enclosing the jaws in the form of 

 piercing organs. The prothorax is free from the other segments 

 of the thorax. The metamorphosis is incomplete. 



