  We present the result of a search for charged Higgs decays of the top quark,
produced in $p\bar{p}$ collisions at $\surd s =$ 1.8 TeV. When the charged
Higgs is heavy and decays to a tau lepton, which subsequently decays
hadronically, the resulting events have a unique signature: large missing
transverse energy and the low-charged-multiplicity tau. Data collected in the
period 1992-1993 at the Collider Detector at Fermilab, corresponding to
18.7$\pm$0.7~pb$^{-1}$, exclude new regions of combined top quark and charged
Higgs mass, in extensions to the standard model with two Higgs doublets.
