Source : Webster's Revised Unabridged Dictionary (1913)

Phantasmagoria \Phan*tas`ma*go"ri*a\, n. [NL., from Gr. ? a
   phantasm + ? an assembly, fr. ? to gather: cf. F.
   phantasmagorie.]
   1. An optical effect produced by a magic lantern. The figures
      are painted in transparent colors, and all the rest of the
      glass is opaque black. The screen is between the
      spectators and the instrument, and the figures are often
      made to appear as in motion, or to merge into one another.

   2. The apparatus by which such an effect is produced.

   3. Fig.: A medley of figures; illusive images. ``This mental
      phantasmagoria.'' --Sir W. Scott.

Source : WordNet®

phantasmagoria
     n : a constantly changing medley or real or imagined images (as
         in a dream)