The scientific publications of the United States National Museum consist of two series — the Proceedings and the Bulletins. The scientific publications of the United States National Museum are intended primarily as a medium for the publication of original, and usually brief, papers based on the collections of the National Museum, presenting newly acquired facts in zoology, geology, and anthropol ogy, including descriptions of new forms of animals, and revisions of limited groups. One or two volumes are issued annually and dis tributed to libraries and scientific organizations. A limited number of copies of each paper, in pamphlet form, is distributed to specialists and others interested in the different subjects as soon as printed. The date of publication is printed on each paper, and these dates are also recorded in the tables of contents of the volumes.