136 Invertebrata. 



a. With suctorial mouths, wings absent, or 



when present having the fore pair 

 thickened. Order Rhynchota. 

 Wings four equal, membranous. Order 

 Thysanoptera. 



b. With masticatory mouths, abdomen with 



a terminal appendix of bristles or a 



bifid tail. No wings. Order Thy- 



sanura. 

 Abdomen with a terminal two-bladed 



forceps. Order Euplexoptera. 

 Abdomen with no appendages, wings with 



reticulated costse. Order Orthoptera. 

 B. Insects which pass through a quiescent pupa stage. 

 a. Mouth masticatory, wings membranous, 



equal. Order Neuroptera, 

 Wings hair-clad or scaly, unequal. 



Order Trichoptera. 



Fore-wings converted into hard wing- 

 covers. Order Coleoptera. 

 A Mouth suctorial, with rudi mental wings 



and compressed bodies. Order Aphan- 



iptera. 



With two wings. Order Diptera. 

 With four wings, the anterior short, 



twisted. Order Strepsiptera. 

 Wings large and scale-covered. Order 



Lepidoptera. 

 Wings naked, membranous, few-veined. 



Order Hymenoptera. 



