  A new algorithm for the derivation of low-density expansions has been used to
greatly extend the series for moments of the pair-connectedness on the directed
square lattice near an impenetrable wall. Analysis of the series yields very
accurate estimates for the critical point and exponents. In particular, the
estimate for the exponent characterizing the average cluster length near the
wall, $\tau_1=1.00014(2)$, appears to exclude the conjecture $\tau_1=1$. The
critical point and the exponents $\nu_{\parallel}$ and $\nu_{\perp}$ have the
same values as for the bulk problem.
