Neutral hydrogen study of 21 small angular diameter galaxies.

Summary. Neutral hydrogen contents, systemic radial velocities and indicative total masses of 21 galaxies with relatively small angular diameters from Sb to irregular types have been measured with the radiotelescope. Determination of systemic radial velocities have been made for 5 galaxies with previously unknown veloci ties; their group membership is confirmed, except for one of them. The effective neutral hydrogen diameters are determined for 6 galaxies. Key words: galaxies - 21-cm radiation - interstellar matter - neutral hydrogen