CLASSIFICATION OF INSECTS. 



63 



List of Orders of the Hexapoda. 



Thysanura. 



Ephemerida. 



Odonata. 



Plecoptera. 



isoptera. 



Corrodentia. 



Mallophaga. 



euplexoptera. 



Orthoptera 



Hemiptera. 



Neuroptera. 



Mecoptera. 



Trichoptera. 



Lepidoptera. 



Diptera. 



Siphonaptera. 



Coleoptera. 



Hymenoptera. 



Physopoda. 



Order Thysanura (Thys-a-nu'ra). 

 Bristktails, Springtails, Fish-moths, and others. 



The members of this order are wingless insects which 

 undergo no metamorphosis, the larval form being retained 

 hy the adult. The mandibles and m.ax- 

 illce are retracted within the cavity of 

 the head, so that only their tips are 

 visible ; they have, however, some free- 

 dom of motion, and can be used for 

 biting and chewing soft substances. 

 True compound eyes are rarely present ; 

 but in some genera there is a group of 

 simple eyes on each side of the head. 

 The abdomen is sometimes furnished 

 with rudimentary legs. 



A familiar example of this order 

 is the fish-moth (Fig. 33), which 

 often does damage to starched cloth- 

 ing, bookbindings, and sometimes 

 loosens wall paper by eating out 

 the paste. The hair line at the 

 left of the figure indicates the length of the insect. 



The fish-moth is one of the bristletails, which are 



iia. 



33. —The 

 moth. 



