  A generalization of the pseudoclassical action of a spinning particle in the
presence of an anomalous magnetic momentum is given. The action is written in
reparametrization and supergauge invariant form. The Dirac quantization, based
on the Hamiltonian analyses of the model, leads to the Dirac-Pauli equation for
a particle with an anomalous magnetic momentum in an external electromagnetic
field. Due to the structure of first-class constraints in that case, the Dirac
quantization demands for consistency to take into account an operators ordering
problem.
