DISTRIBUTION OF INSECTS INTO ORDERS. 29 



into the larger groups as it is to regard them as orders equivalent 

 with the great ones, such as Coleoptera, Lepidoptera, &c. It is 

 indeed impossible not to be convinced that in many of these groups 

 the structure of one order is partially lost, and that of the adjacent 

 one assumed, whence it would be as correct to place the insects in 

 the one as in the other order. Indeed, it appears to me to be the 

 strongest evidence of the forcing of nature to a preconceived system, 

 when we see introduced amongst a number of animals, characterised 

 by a constant peculiarity of structure in some important organs, an 

 animal, or group of animals, which does not possess such character, 

 and find such a step attempted to be justified on the plea that this 

 organ is variable in other groups. 



With a view to avoid some of the inconveniences which still exist 

 in the distribution of insects, I would propose the following classifi- 

 cation in which the approach of the Hymenoptera to the Trichoptera, 

 and of the Lepidoptera towards the Diptera, as pointed out by Mac 

 Leay, together with the direct passage between the Trichoptera and 

 Lepidoptera, and the descending series in the first, and the ascending 

 series in the second columns must be borne in mind. 



CLASS OF HEXAPOD METAMORPHOTIC INSECTS. 



Subclass, Month with jaws. Subclass, Mouth ivith a sucker. 



(Dacnostomata TV.) (Antliostomata W.) 



Ord. Hymenoptera. Ord. Diptera. 



? Osculant Ord. Strepsiptera. ? Osculant Ord. Homaloptera. 

 Ord. Coleoptera. ? 0?,cu\iinX.Ov{\.Aphaniptera.* 



Osculant Ord. Euplexoptera (Earwig). 

 Ord. Orthoptera. Ord. Heteroptera (includ- 



ing the Water Bugs). 

 ? (Thrips?)t ? 



Ord. Neuroptera. Ord. Homoptera. 



? ? 



Ord. Trichoptera (Phryganea alone). Ord. Lepidoptera. 

 ? ? 



Moreover, the relationships existing between the opposite orders 

 must not be overlooked. Since, in some instances, as between the 



* The relationship of the Flea with tlie Hymenoptera, insisted upon by Strauss, 

 does not appear to me to be well founded. 



f Order Thysanoptera Holiday, by whom an elaborate paper upon this tribe of 

 remarkable insects has been published in the EntomoLMac/. No. 15. April, 1 83G. 



