  We study the Landau levels associated with electrons moving in a magnetic
field in the presence of a continuous distribution of disclinations, a magnetic
screw dislocation and a dispiration. We focus on the influence of these
topological defects on the spectrum of the electron(or hole) in a magnetic
field in the framework of the geometric theory of defects in solids of Katanaev
and Volovich. The presence of the defects breaks the degeneracy of the Landau
levels in different ways depending on the defect. Exact expressions for
energies and eigenfuctions are found for all cases.
