Complex sentence: The exact number of such shorts, known popularly as Bunnygraphs or Bunnyfinches, is unknown because Vitagraph's films were not generally archived and most are now lost: estimates range from over 150, to over 200, to over 260.
Split into simpler sentences: The exact number of such shorts, known popularly as Bunnygraphs or Bunnyfinches, is unknown because Vitagraph's films were not generally archived. Most are now lost; estimates of the number produced range from over 150, to over 200, to over 260.