CHAPTER XXI. 



Order Coleoptera (Co-le-op'te-ra). 



The Beetles. 



The members of this order have a pair of horny wing-covers, 

 called elytra, which meet in a straight line down the back, and 

 beneath which there is a single pair of membranous wings. 

 The mouth-parts are formed for biting. The metamorphosis 

 is complete. 



Beetles can be readily distinguished from all other in- 

 sects except earwigs by the possession of horny, veinless 

 wing-covers which meet in a straight line down the back 



(Fig. 599); and they differ from ear- 

 wigs in lacking the pincer-like ap- 

 pendages at the tail end of the body 

 characteristic of those insects (see 

 page 103). Beetles also differ from 

 earwigs in having a complete meta- 

 morphosis. 



The name of the order, Coleop- 



FlG 599. tera, is from two Greek words: coleos, 



a sheath; and pteron, a wing. It refers to the sheath-like 



structure of the elytra (el' y-tra) or wing-covers, which are 



modified wings. 



The structure of the elytra is so different from that usu- 

 ally characteristic of wings that F. Meinert was led to be- 

 lieve that they were not wings, but greatly enlarged paraptera 

 of the mesothorax; and unfortunately this view was adopted 

 in the earlier editions of this book. 



The reasons in support of Meinert's view are the follow- 

 ing : the difference in the structure of elytra from that of 

 wings ; the fact that in the Lepidoptera the paraptera of the 



4Q4 



