  In Einstein's gravity, the entropy of horizons is proportional to their area.
Several arguments given in the literature suggest that, in this context, both
area and entropy should be quantized with an equally spaced spectrum for large
quantum numbers. But in more general theories (like, for e.g, in the black hole
solutions of Gauss-Bonnet or Lanczos-Lovelock gravity) the horizon entropy is
\emph{not} proportional to area and the question arises as to which of the two
(if at all) will have this property. We give a general argument that in all
Lanczos-Lovelock theories of gravity, it is the \emph{entropy} that has equally
spaced spectrum. In the case of Gauss-Bonnet gravity, we use the asymptotic
form of quasi normal mode frequencies to explicitly demonstrate this result.
Hence, the concept of a quantum of area in Einstein Hilbert (EH) gravity needs
to be replaced by a concept of \emph{quantum of entropy} in a more general
context.
