THE publication of the first volume of Mr. Kirby's Catalogue of Heterocera cannot fail to be regarded as a great event amongst students of exotic moths, and should mark an epoch from which is to commence the great work of reducing the vast amount of material they have to deal with to some kind of system and order, from the state of chaos produced by the greater number of those who have taken up the subject continuing to describe innumerable species, forms, and varieties, without any systematic study or attempt to define the limits of the families and genera they placed them in. So vast and scattered was the literature on the subject that it was almost hopeless to attempt to discover even how many species had been described in any given genus, or to say with any certainty that the forms to be dealt with had not been described by other authors; and if the subject in hand was the study of a local fauna, and not the monographing of a group, the only plan it was possible to adopt was to place the species in approximately the right genus and trust more or less to chance, according to the availability of large collections for consultation, that they had not been described elsewhere. Students will now have no such excuse for inexact work, and, up to the end of the numerous and very remotely connected groups of families known as the Bombyces, will have a complete and easily consulted catalogue of all described species, with the localities they come from, so that they will be able to see at a glance to which species the forms they are trying to identify are most likely to belong, and having full references to the books in which they are described their labours will be lightened by almost half, as students of the European fauna who have had Staudinger's catalogue to help them will fully appreciate. No one but Mr. Kirby who has lived his life among the books on the subject, and has been collecting his materials for the last twenty years, as he tells us in his preface, could have made the catalogue as complete as he has done, and though it is of course impossible that such a volume could have been put together without a few errors and omissions creeping in, yet some months of work with the advantage of being constantly able to borrow the proof sheets has shown how extremely few these are.