  We have completed a 21-cm survey of a 600 square degree region of the
Centaurus A group of galaxies at a redshift of ~500 km/s as part of a larger
survey of the entire southern sky. This group of galaxies was recently the
subject of a separate and thorough optical survey (Cote et al. 1997), and thus
presented an ideal comparison for us to test the survey performance. We have
identified 10 new group members to add to the 21 already known in our survey
area. Six of the new members are previously uncatalogued galaxies, while four
were catalogued but assumed not to be group members. Including the 7 known
members outside of our survey area, this brings the total known number of Cen A
members to 38. All of the new HI detections have optical counterparts, most
being intrinsically very faint (M(B) > -13.0), late-type low surface brightness
dwarfs. Most of the new members have HI masses only a few times our survey
limit of 10(7) M(solar) at an assumed distance for the group of 3.5 Mpc, and
are extremely gas-rich, with a median M(HI)/L(B) > 1. Our limiting HI
sensitivity was actually slightly worse than the HI follow-up observations of
the Cote et al. optical survey, yet we have already increased the known number
of group members by 50% using an HI survey technique. While we have increased
the known NUMBER of members by ~50%, these new members contribute < 4% to its
light.
