392 SYSTEM OF INSECTS. 



thing like elytra and a scutellum appear to distinguish 

 these insects. 



DEF. Metamorphosis incomplete. 

 Body apterous, compressed. 

 Mouth rostrulate*. 



Tarsi pentamerous. 







We are now come to those insects which, though they 

 change their skin in their progress to their state of per- 

 fection, and some of them, as we have seen 5 , gain addi- 

 tional segments and pairs of legs, yet none of them ac- 

 quire wings or wing-cases : these I have considered as 

 forming one Order, under the denomination of 



12. APTERA C (Synistatdy Antliata, Unogata, Mito- 

 sata F.). I do not give this as a natural Order. Our 

 knowledge, however, of the internal organization of its 

 groups, is not at present sufficiently matured to warrant 

 the formation of them into new Classes' 1 : till that is more 

 fully ascertained, it seems to me therefore best to con- 

 sider these groups as forming three Suborders : thejirst 

 consisting of the Hexapods; the second of the Octopods; 

 and the third of the Polypods. It will be better, I think, 

 instead of giving a general character of the Order, 

 which principally consists in the insects composing it 

 being Apterous^ or never acquiring organs of flight, to 

 define each of these groups. 



Hexapods '(Ametabolia Leach, Ametabola M C L.). Six 

 legs may be regarded as the natural number in all the 



a VOL. III. p. 470. b Ibid. p. 23. 



c From #,priv, and irregw. d VOL. III. p. 221 . 



