  (Abridged) We have used optical spectroscopy to investigate the radio-
selected active galaxy populations in a sample of 20 nearby Abell clusters. The
spectra were used to characterize the galaxies as AGN or galaxies forming stars
at rates comparable to or greater than the Milky Way. A significant population
of star forming galaxies with large amounts of nuclear dust extinction were
revealed. This extinction eliminates bluer emission lines such as [OII],
meaning their star formation could easily be overlooked in studies which focus
on such features. Around 20% of cluster star forming galaxies have such
spectra, and their radial distribution suggests they are the consequence of
some cluster environmental effect. We note that galaxies of this type may be
identified using their 4000-Angstrom break strengths. We also find that
discrepancies in reported radio luminosity functions for AGN are likely the
result of classification differences. There exists a large population of
cluster galaxies whose radio fluxes, FIR fluxes, and optical magnitudes suggest
their radio emission may be powered by stars, yet their spectra lack emission
lines. Understanding the nature of these galaxies is critical to assessing the
importance of AGN in the radio luminosity function at low luminosities.
