ENTOMOLOGY 



to a hypothetical form like the trochosphere larva of recent 

 polychsete annelids. 



Orders of Insects. Linnaeus arranged insects in seven 

 orders, namely, Coleoptera, Hemiptera, Lepidoptera, Neurop- 



FlG. 



FIG. 10. 



Campodea. Length, 

 3 mm. 



Lepisma. Length, 

 10 mm. 



tera, Hymenoptera, Diptera and Aptera. The wingless in- 

 sects termed Aptera were soon found to belong to diverse 

 orders and the name has now become so ambiguous as to meet 

 with little approbation. 



From the Linnsean group Hemiptera, the Orthoptera were 

 set apart; the old order Neuroptera, a heterogeneous and 

 unnatural group, has been split into several distinct orders, 

 and many other changes in the classification have been neces- 

 sary. 



Without entering any further into the history of the sub- 

 ject, it is sufficient to say that increasing discrimination on the 



