THE ORDER COLEOPTERA. 



43 



are grubs which undergo a complete metamorphosis 

 in the course of their development. 



3. Select one of the larger beetles, and examine its 

 wing-covers, or elytra, as they are called. Remove 

 them, and note their structure. How do the elytra 

 of beetles differ from the front wings of locusts? 



4. Study the hind wings. How does the folding 

 of the hind wings of a beetle differ from that of the 

 hind wings of a locust ? 



J. Mount the elytra and hind wings of the beetle 

 on a card. 



6. Study the mouth-parts of the beetle, dissecting 

 them out, and mounting them on a card as was done 

 with the mouth -parts of a locust in Lesson III. 

 Label each of the mouth-parts. 



7. Remove some of the upper rows of beetles in 

 your case so as to make room for the two cards just 

 prepared, and place the cards immediately below the 

 label for the order. Then rearrange the beetles be. 

 low the cards. 



8. We have now observed the more important 

 characteristics of the order Coleoptera or beetles, 

 which are as follows : 



Order Coleoptera. — 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. 



