5954 



Northern Entomological Society. 



to be assigned to the orders themselves, based on the nature of the metamorphosis, 

 Vrogressing in each division from the highest rank to the lowest. 



" On this system I shall adopt the classification proposed by Mr. Dallas, 

 with but little other alteration than the sinking of the minor orders. 



" The class Insecta, then, will be divided into three sections: — 



"I. Meta BOLA. — Insects undergoing a metamorphosis which is termed complete ; 

 the pupa unable to take food, and being for the most part quiescent. This 

 section comprises 



Order 1. Coleoptera. 



2. Hymenoptera. 



3. Diptera. 



4. Lepidoptera. 



5. Trichoptera. 



"II. Hemimetabola. — Metamorphosis semicomplete ; the pupa being active and 

 able to feed. This comprises 



Order 6. Neuroptera. 



7. Orthoplera. 



8. Hemiptera. 



9. Homoptera. 



"III. Ametabola.' — Without metamorphosis, undergoing only a change of skin; 

 comprising the apterous insects called spring-tails, lice, and bird-lice. 



Section I. 



"1. Coleoptera, Westwood says, 'This order comprises the extensive tribes of 

 beetles, and, in respect to the size of some of these insects, or the number of individual 

 species, must be regarded as occupying the foremost rank amongst insects.' The 

 pupa is covered by a thin skin, through which the limbs are visible. 



"2. Hymenoptera, In the preparatory states, and the mandibulated mouth of the 

 perfect insects, this order has a close affinity with the Coleoptera. The larvce of the 

 Tenthredinidge, however, make an approach to those of the Lepidoptera. 



" 3. Diptera. As one reason for placing the Diptera next, observe what Westwood 

 says, in speaking of the Hymenoptera : ' It seems to be admitted on all hands that 

 the insects, which are the real analogues of the present order, exist in the Dipterous 

 order, almost every Hymenopterous group having its representative in the latter. 

 Mr. McLeay has also noticed the apodal structure of the larvae as analogous in both 

 orders.' There are two forms of pupa among the Diptera, the extricated and the ob- 

 tected ; the former most resembles the pupa of the liCpidoptera ; in the latter the skin 

 of the larva is not shed, but hardens and forms, as it were, a cocoon. The pupae of 

 the Culicidae and Chironomidae are aquatic and are active ; but their movements are 

 not by means of legs, and differ totally from those of the pupae of insects belonging to 

 the second section. 



" 4. Lepidoptera. The position here given to this order is partly explained above. 



