It is twenty-six years since the original list was published and nothing can better illustrate the advances made than a comparison between the old and the new Glossary. No one realizes better than I the fact that as students have increased in each order, each has followed an independent line of research, absolutely without regard to the work done elsewhere. In consequence, we have several terms for the same thing in many cases and, in an equal number, several meanings to the same term. As no one man can now-a-days cover the entire field of Entomology, it goes without saying that I was compelled to rely partly upon books and partly upon the good nature of correspondents to make the work even approximately complete. The first notable contribution came from Professor Justus W. Folsom, of Urbana, Illinois, who sent me over 2000 cards of terms collected by himself and his assistants, and these added materially at the beginning of the work. A number of correspondents were good enough to send in lists of terms in Coleoptera, Lepidoptera, Orthoptera, Hemiptera and Neuroptera, and to refer me to literature where explanations of other special terms could be found. After the cards were so far advanced as to warrant a preliminary manuscript, Dr. Philip P. Calvert of the University of Pennsylvania. Mr. Nathan Banks of Washington, D.C., and Mr. C. W. Johnson of the Boston Society of Natural History went carefully over the entire work and by their criticisms and additions contributed materially to such merit as it possesses. To these gentlemen and to the many others not specifically mentioned I give thanks for their assistance, and if there have not been more co-workers it has been only because of the time element that seems to demand the best that is ready, rather than a delay to secure perfection. It would be interesting to go at length into the history of the correspondence to determine what sort of terms should or should not be included and to bring out the hopeless divergencies existing; but all that is important here is to state briefly what has been included and what omitted.