  We formulate world-volume actions that describe the dynamics of Dirichlet
p-branes in a flat 10d background. The fields in these theories consist of the
10d superspace coordinates and an abelian world-volume gauge field. The global
symmetries are given by the N=2A or N=2B super-Poincare group, according to
whether p is even or odd. The local symmetries in the (p + 1)-dimensional world
volume are general coordinate invariance and a fermionic kappa symmetry.
