  We examine several aspects of the formulation of M(atrix)-Theory on ALE
spaces. We argue for the existence of massless vector multiplets in the
resolved $A_{n-1}$ spaces, as required by enhanced gauge symmetry in M-Theory,
and that these states might have the correct gravitational interactions. We
propose a matrix model which describes M-Theory on an ALE space in the presence
of wrapped membranes. We also consider orbifold descriptions of matrix string
theories, as well as more exotic orbifolds of these models, and present a
classification of twisted matrix string theories according to Reid's exact
sequences of surface quotient singularities.
