  We examine the construction of the spin angular momentum in systems with
pseudoclassical Grassmann variables. In constrained systems there are many
different algebraic forms for the dynamical variables that will all agree on
the constraint surface. For the angular momentum, a particular form of the
generators is preferred, which yields superselection sectors of irreducible
spin^c(n) representations rather than reducible so(n) representations when
quantized in the Schr\"odinger realization.
