Systematic zoologists the world over will welcome the announcement by the Council of the Zoological Society of London of its plans for the preparation of as complete a list as possible of all generic names that have been used in Zoology from the tenth edition of Linnaeus through 1935. It is estimated that nearly 200,000 names will be included, and 1937 has been set as a possible publication year. The society has invited all systematists and others interested in the production of such a work to report any names of genera or subgenera (with reference to the original place of publication) that appear to have been omitted from existing records or catalogues. This work, especially if it can be brought out at a price moderate enough to assure wide distribution among zoologists and libraries, will go a long way toward reducing the number of homonyms in zoological nomenclature. Homonyms, or names found to be preoccupied elsewhere in Zoology, are one of the impedimenta that clutter up taxonomy; and there are altogether too many of them. (I have found more than a dozen myself in the past year, and I see only a small part of taxonomic literature.) In the case of species and subspecies, homonyms occur relatively infrequently, but not so with genera, for generic names seem to be very scarce, iudged by the many instanc's of preoccupation that occur and subsequently have to be corrected under Article 34 of the International Rules of Zoological Nomenclature.* It must not only be rather embarrassing for an author to discover or be told that his proposed name is preoccupied, but for all concerned it is a nuisance and an expense to make the corrections required. In cases where the homonym is not discovered until after the name has been published sometimes in many places, the awkwardness of it is all the more evident. Homonyms are usually inadvertent and result from the lack of any syste-matic attempt on the part of the author to make certain that his proposed name is available. Perhaps he does not have the necessary reference books readily at hand, or, having consulted one nomenclator, he takes that as final. In other cases he may not know just where to look. It may serve a very useful purpose, therefore, to list together here the most important zoological nomenclators, so that an author may be reasonably certain that he has exhausted the possibilities in checking individual names, particularly genera. The chief works of this kind are as follows: