Neutral hydrogen in binary and multiple galaxies.

H I observations of 28 galaxies, performed using the 305 m antenna at the 21 cm line, are reported for those galaxies belonging to pairs or small groups. The Arecibo beam is the primary H I distribution detector, and the size, flux and mass, redshift and rotation velocity, and spin orientation for each object are presented. Total indicative mass in individual galaxies and individual mass-to-light ratios, and nominal pair mass (for each pair, only statistically valid), are derived. It is noted that total mass-to-light ratios tend to be very similar within pairs. H I contour maps are included.