OF THE ANNULOSA. 369 



been occupied by species now extinct. These chasms 

 are indeed in some cases very wide ; but, on the other 

 hand, we often see the orders passing gradually into one 

 another, as the Hemiptera and Homoptera, the Coleo- 

 ptera, Orthoptera, Neuroptera and Trichoptera ; so that, 

 where any void occurs, it is difficult not to imagine that 

 it must result rather from the imperfection of our know- 

 ledge of created species than from any other cause what- 

 ever. 



We shall now return to the Coleoptera, which, previ- 

 ously to this general dissertation on Winged insects, we 

 left connected with the Ametabola ; and thus we may en- 

 deavour to trace those circumstances of affinity Which the 

 column of 



Mandibulata 

 evidently displays. 



The Coleoptera are universally admitted to be connected 

 with the Orthoptera, by means of the Forjicula, which, 

 though now placed by Latreille and others in the latter 

 order, formerly with Linnaeus brought up the rear of 

 the Coleoptera. The mere aspect of the genus Man- 

 tispa is sufficient to satisfy us that the Neuroptera ought 

 never to have been separated from the Mantidte. And 

 so truly is a Trichopterous insect connected with the 

 Neuroptera, that it is only within the last few years that 

 Mr. Kirby has revived the opinion of Degeer that it belongs 

 to a distinct order. Thus far our path has been smooth ; 

 but now we have to determine to which of the other 

 Mandibulata the Trichopterous insects lead. An evident 

 hiatus is visible in this place; but we cannot do better, 

 perhaps, than follow the example of such entomologists as 

 Linnaeus and Latreille, and pass at once to the Tenthre- 

 dines. Hence to the Hymenoptera the passage is easy ; 



2 B 



