ON THE STRUCTURE AND FUNCTIONS OF WORMS. 23 



four wings covered with fine scales apparently like powder or meal ; as the Butterflies 

 and Moths. 



4. Neuropterous insects (from nvpa* a nerve, and rttfpov a wing,) have foul 

 membranaceous, transparent, naked wings, in which i.he membranes cross each other 

 BO as to appear like net-work. The tail has no sting, but is sometimes furnished 

 with appendices like pincers, by which the males are distinguished. The common 

 Dragon-fly is the best example that can be brought to illustrate this order ; and the 

 genus Phrygenea forms an exception with respect to the net-work appearance of lha 

 wings. 



5. Hymenoplerous insects (from v^v a membrane, and rtrfpov a wing.) The insects 

 belonging to this order have generally four membranaceous naked wings : the 

 neuters, however, in some of the genera, and in others the males or females, are des- 

 titute of wings. The wings do not so much resemble net-work as those of the last 

 order. The tail, except in the male, is armed with a sting. The Bee, the Wasp, 

 and the Ant are of this tribe. 



6. Dipterous insects (from 5trf?ioo$ double, and Ttrtpoi/ a wing,) are those which have 

 only two wings, each furnished at its base with a poise or balancer. The common 

 House-flies and the Gnat are familiar examples of this order. 



1. Apterous insects (from a without, and jittpov a wing.) This order contains all 

 Bucb insects as are destitute of wings in both sexes ; as the Spider, the Flea, and the 

 Louse. 



