When we find an insect so doubtfully situated between two classes, that Linnæus placed it in Neuroptera, Fabricius in Orthoptera, Latreille, in two of his works, in Orthoptera, and in two others in Neuroptera, MacLeay in Neuroptera, and Kirby and Spence in Orthoptera, I think it but fair to conclude, that the orders must approach very nearly to admit of this difference of opinion: such is Mantispa; and Mantis-like as it really is, it only borrows that appearance from being on the extreme circumference of the Neuropterous circle, and touching the Orthopterous one where Mantis must evidently be situated. Lastly, we see in Psocus the form, wings, and whole appearance of Aphis, so exquisitely imitated, that practised entomologists often, nay mostly, fail in separating them correctly: thus we find that class VII. contains five natural orders, the contents of which have been--and may be again, should the linear and dichotomous system continue in vogue--placed either in the class to which they truly belong, or respectively in classes I. II. III. V. and VI. at the mere option and caprice of the systematist. I have already admitted that I find no neuropterous insect sufficiently related, in its final state to class IV. to warrant my placing it in contact with that class; and that I may not be accused of assuming facts which exist only in my imagination, I am perfectly willing to conclude that no such insect is to be found; a conclusion that time and discovery, by falsifying, can only add yet one more buttress to a tower, which nature seems to point out as built by herself.