I have always made it a rule of my conduct to promote Natural History by every method in my power. My cabinet has therefore been open to all those gentlemen, from whatever part of the world they came, who made Entomology their study. In consequence of this permission, descriptions of many of the insects now published have got abroad some time since, and even figures of several of them have made their appearance. This I did not expect, as many of my plates were entirely finished some months, and even years, before those above-mentioned could have got forth. This will account for the seeming contradiction in many places, upon comparing the descriptions with the Index, where many insects are described and mentioned as _new_ ones, but in the Index have their synonyms given in various authors. The truth is, the descriptions were made about the year 1775, between which time and the present those authors published their respective works. But who can foresee disappointments, or avoid their effects? It may be urged, that these plates might have been omitted, and others substituted. In so doing, however, I could {iv}not have been justified, either to the purchasers of the former volumes, or to myself. Many of them, there is no doubt, would not have the figures of those insects alluded to, unless in this work; and, as to my part, without considering the loss, neither my business, my health, nor my leisure, would have enabled me to supply their place. This very circumstance I have mentioned in the Preface to my last volume, wherein I bespoke the candour of my readers for an _anticipation_ of a similar kind, which got abroad before I could bring out that volume. In the present case, I have the greatest reason to request the same indulgence from a motive still stronger, which is, that almost all the figures given by other authors, and which I have quoted in the index, were taken from specimens originally in my possession. As it is, I hope, the novelty, the beauty, and the curiosity of the other insects herein published, will, by affording large gratification to the inquisitive naturalist, make some amends, and that the nature of my situation will procure me a full acquittal from any kind of premeditated imposition. In regard to the manners and economy of the insects now published, I have been able to get little information. There are very few, even of those who collect abroad, who will give themselves the trouble of making observations; and such as do not want inclination or ability, and even travel expressly for the purpose, find great, and to us almost inconceivable impediments.