DEFINITION OF THE TERM INSECT. 27 



prove that the types of form in one natural group or 

 class are reproduced in another; this appears to result 

 from the following parallel series : 



Ncuropterous Aptera. Arachnida. Crustacea. 



Larva;. 

 Psocus Hexapoda Galeodes Larunda. 



Myrmeleon Phalangium. . . . Aranea.... < , " 



Octopoda fDecapoda ma- 



Panorpa i Chchfer Scorpio < , . „ 



1 J J tassma bcorpio 



v- especially. 

 Ephemera Myriapoda ##### Isopoda. 



No type representing the Myriapoda has yet been 

 discovered in the Arachnida class; but I have little 

 doubt of its existence. You will observe that the ana- 

 logies between the larvae of the winged orders and the 

 Aptera were first noticed by Mr. W. MacLeay a . It is 

 probable that these parallel series of representatives of 

 each other might be increased, as well as the numbers in 

 the respective columns. 



What I have said will, I trust, sufficiently justify me 

 for making at present no more material alterations in the 

 classification I long since proposed to you b ; I shall, 

 therefore, now proceed to define the objects I consider as 

 Jnsecta; but I shall first observe — that as Latreille con- 

 siders the branchiopod Crustacea or Entomostraca of 

 Miiller as entitled to the denomination of Crustaceo- 

 Arachnida c ; so his Trachean Arachnida might be called 

 Arachnido-Insecta, and his Myriapoda, Crustaceo-Insecta. 



a Hot. Entomolog. 422—. 



b See above, Vol. I. 4th Ed. p. 66. Note \ 



c Surely the denomination ought to have been Arachnido-Crustacea, 

 since the learned author considers them as belonging to the Crustacea 

 class, . 



