THE THORAX OR TRUNK. 



53 



The first pair are usually attached to the mesothorax, 

 and the second to the metathorax. According to their 

 substance, they are termed elytra, tegmina, hemelytra, 

 and icings. 



The first three of these words, i. 6., elytra, tegmina 

 and hemelytra, are used to designate the first or forward 

 pair of wings, when they are developed as icing-covers, 

 as cases or organs of protection for the second pair which 

 is such, are exclusively used as organs of flight. 



BASE or UNDER SIDE OF WING CASE OP GREEN GRASS- 

 HOPPER BY WHICH THE SOUND IS PRODUCED, (aCEIDA 



viridissima). 



The elytra are such as the hard and often beautifully 

 marked wing covers of the beetles or coleoptera. 



By t^e term tegmina are designated the straight, 

 shield-like wing covers of such insects as the grasshop- 

 pers, locusts, katy-dids, and the like. 



