Preparation of a desk-side reference manual of Cretaceous foraminifera was undertaken as a project of the Bureau of Economic Geology, where I was a staff member during the summers of 1945 to 1947 and during July of 1951. Although the Handbook is intended primarily for the advanced college-level student and routine commercial laboratory micropaleontologist, it should be useful as well to the specialist. The accuracy of a compilation of this kind is never greater than that of the sources from which it is taken, and errors of transcription and interpretation are unavoidable. If the Handbook proves as valuable to micropaleontologists in general, however, as I have found the manuscript to be during the time of its accumulation, its purpose will be well served.