We present a geometric formulation of super p-brane theories in which
the Wess-Zumino term is (p + 1)-th order in the supersymmetric current
s, and hence is manifestly supersymmetric. The currents are constructe
d using a supergroup manifold corresponding to a generalization of a s
uperalgebra which we found sometime ago. Our results generalize Siegel
's analogous reformulation of the Green-Schwarz superstring. The new s
uperalgebras we construct underly the free differential superalgebras
introduced by de Azcarraga and Townsend a few years ago.