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We have obtained B and V photometric CCD images of a southern sample of HI-selected, low surface brightness galaxies in the Local Supercluster. These observations have revealed a surprising range of types of objects within this nearby sample, which is completely composed of faint, gas-rich, galaxies originally classified as extremely late-type, e.g., Im, Sm, or Sdm, on deep photographs taken with Schmidt telescopes. In particular, we find examples of low surface brightness systems which exhibit spiral structure or have symmetric bars, even in galaxies with small sizes or low masses. We will present basic optical properties, such as luminosities, isophotal diameters, surface brightnesses, and B-V colors, of these classes of extremely late-type galaxies. These properties will be contrasted with similar data for normal, less well-organized field irregular galaxies, and for a sample of extremely late-type galaxies in the Virgo Cluster. The results will be discussed in terms of evolution and star-forming histories of extremely late-type field galaxies.
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