ABSTRACT Hoffman, G. Lyle AST-9316213 Radioastronomical observations and analyses will be made to continue a long-term study of how galaxies aggregate on various scales from small groups through superclusters, of the nature and properties of particular morphological types of galaxies, and physical processes affecting the outermost edges of HI disks. Data from the Arecibo Observatory for two samples of galaxies will be analyzed. Observations of faint candidate members of all groups within the declination range of the Arecibo telescope will be observed and analyzed to study the extension of the Tully-Fisher relation to fainter objects, to obtain even more precise distances to the groups, and to investigate the dynamics of the individual groups as well as the tidal influences on them produced by the Local Supercluster and more distant mass concentrations. ***
