rhodophane

from The Collaborative International Dictionary of English v.0.48

Rhodophane \Rho"do*phane\ (r[=o]"d[-o]*f[=a]n), n. [Gr. "ro`don
   the rose + fai`nein to show.] (Physiol.)
   The red pigment contained in the inner segments of the cones
   of the retina in animals. See {Chromophane}. --W. K["u]hne.
   [1913 Webster]