  We discuss a set of novel discrete symmetry transformations of the N = 4
supersymmetric quantum mechanical model of a charged particle moving on a
sphere in the background of Dirac magnetic monopole. The usual five continuous
symmetries (and their conserved Noether charges) and two discrete symmetries
together provide the physical realizations of the de Rham cohomological
operators of differential geometry. We have also exploited the supervariable
approach to derive the nilpotent N = 4 SUSY transformations and provided the
geometrical interpretation in the language of translational generators along
the Grassmannian directions onto (1, 4)-dimensional supermanifold.
