The date of issue of a work containing a new scientific name determines the date the name is available and, therefore, the priority of the name with respect to other applied to the same taxon. Differences between the dates printed in publications and the actual dates of issues often resulted from procedures in distribution and erratic publishing schedules, especially before the twentieth century. Distribution, including that to subscribers, was usually the responsibility of the author (Jackson, 1975: 14-15). Early publications were customarily issues in parts (Price, 1982) and the dated title page was usually issued last, which complicates matters of establishing an actual publication date.

Early bibliographic works, especially those of Sherborn (e.g., 1902-1933), Mathews (e.g., 1911, 1919, 1925), Waterhouse (e.g., 1885, 1889, 1937), Zimmer (1926), and Richmond (e.g., 1899b, 1902, 1917), have provided information on the actual dates of issue of many ornithological works. Many modern publications (e.g. American Ornithologists' Union [A.O.U.], 1957, 1983; various volumes of Peters's check-lists) have neglected recent, and some older, bibliographic works on several sources of scientific names of birds that affect the proper citations. Here, we clarify information on the dates of issue of some publications on North American (sensu, A.O.U., 1983) birds. In the event the actual day of issue cannot be determined, the last day of the month or year, whichever was known, or, lacking such information, the printed date, is the date of availability of the scientific name (International Commission on Zoological Nomenclature, 1985: Article 21). Sources for determining the dates of issue include bibliographic works and the invaluable notes of Charles W. Richmond (in the Division of Birds library, Smithsonian Institution). In the following, books are listed alphabetically by the author of the scientific names, and journals by the first word in their title.