  In a recent Letter [Phys.Rev.Lett., 77,4536 (1996), chao-dyn/9609014] Altland
and Zirnbauer claim that they rigorously proved the complete analogy between a
(classically chaotic) dynamical system and disordered (random) solids. The
purpose of this Comment is to show that, in fact, their theory fails to take
into account dynamical features which go beyond standard random matrix theory
description.
