022 TAXONOMY. 



I. Insecta ametabola. 



The larva resembles the perfect insect, yet it wants wings if the 

 perfect insect be winged; the pupa in this case have their rudi- 

 ments ; it runs about and eats. 



a. With sticking mouths, which consist of four tine setae, lying 



in a sheath; palpi are wanting; four biliary vessels, and 

 generally a free prothorax. 



1. Order Hemiptera. 



b. With mandibulate mouths : mandibles and maxillae distinct, 



the latter having palpi, and generally distinct large supe- 

 rior lip. 



a. Four unequal wings ; the anterior ones leathery or parch- 

 menty, the posterior ones folded longitudinally and also 

 once transversely ; prothorax always free ; many biliary 

 vessels. 



2. Order Orthoptera. 



/3. Four, generally equal, more rarely unequal wings, never 

 folded, or sometimes none at all : in the first case the 

 nervures are usually reticulated, and generally many biliary 

 vessels ; in the last case four biliary vessels, attached to 

 the. intestine ; prothorax sometimes free, sometimes not. 



3. Order Dictyotoptera. 



II. Insecta metabola. 



The larva is a worm, consisting of thirteen segments, either with 

 or without legs; the pupa is quiet, or if it moves it does 

 not eat. 



a. Four equally large or equally long wings, with reticulated 



nervures ; mandibulate mouths ; few, four or eight, biliary 

 vessels, rarely more ; prothorax always free. 



4. Order Neuroptera. 



b. Wings always unequal, the posterior ones sometimes want- 



ing, rarely all. 

 a. Mouths adapted to sucking. 



a. a. Instead of posterior wings there are pediculated knobs, 

 yet the wings are sometimes wholly wanting ; four biliary 

 vessels ; larvae apods ; a soft proboscis in the mouth, with 

 several setae and a pair of palpi ; prothorax not free. 



5. Order Diptera, 



