Named in honor of William F. van Altena, well-known astrometrist at the Yale University Observatory. His contributions include works on stellar proper motions and parallaxes, including a revised edition of the Yale Catalogue of Stellar Trigonometric Parallaxes. The southern proper motion program with respect to galaxies is conducted under his direction with the 0.5-m astrograph at El Leoncito. (M 9477) _ _.