GROUPING OF INSECTS. 



lOfj 



The following diagrani shows, in a nulc way, the relative 

 rank and affinities of the eight orders, and of the two series 

 of Six-footed Insects. 



Neuroptera. 

 Thysanura. 



Through Lejnsma, and Podura which are wingless Thysa- 

 nurous insects, the lower series is connected with the Myriopods, 

 the minute degraded Fauropus and Scolopendrella perha})s 

 forming the connecting links ; and through the wingless 

 flies, Brcmla^ Chionea, and Nycteribia, the Diptera, belonging 

 to the higher series, assume the form of the Spiders, the head 

 being small, and sunken into the thorax, while the legs are 

 long and slender. The first and highest series culminates in 

 A2ns, the Honey-bee ; and the second, or lower, in Cicindela, 

 the Tiger-beetle. 



regarding the rank and valne of the minor groups. Professor Agassiz extended 

 Leuckart's views in considering the seven grand divisions of the order of Ilexapods 

 as suborders. In 1803 (How to Observe and Collect Insects, jNIaine Scientific Sur- 

 vey, and Synthetic Types of Insects, Boston Journal of Natural History), we 

 proposed a new classification of these divisions, by which they are thrown into 

 two main groups headed by the Hymeuoptera and Coleoptera respectively. These 

 two groups, as represented in tlie diagram, are nearly equivalent in value, ami 

 stand in a somewhat parallel relation. Tliere is nothing like a linear series in the 

 aiiimal kingdom, but it is like a tree. Tlie hiiilier series of orders form more 

 of <a linear scries than the lower series, so that in the diagram the Xeuroptera, 

 Orthojitera, Hemiptera, and Coleoptera form a more broken series than the Hy- 

 menoptera, Lepidoptera, and Diptera. A Bee, Butterfly, and House-fly are much 

 more closely allied to each other than a Beetle, a Squash-bug, a Grasshopper, 

 «nd a Dragon-fly are among themselves. The Xeuroptera are the most indepen- 

 dent, and stand at the bottom of and between the two series, thougli by the Orthop- 

 tera they are very intimately linked with the Hemiptera and Coleoptera. 



