  This note has two purposes: First, to present a counterexample to a
conjecture parametrizing the simple modules over Green biset functors,
appearing in an author's previous article. This parametrization fails for the
monomial Burnside ring over a cyclic group of order four. Second, to classify
the simple modules for the monomial Burnside ring over a group of prime order,
for which the above-mentioned parametrization holds.
