  We provide a simple way to obtain the fusion rules associated with elementary
quasi-holes over quantum Hall wave functions, in terms of domain walls. The
knowledge of the fusion rules is helpful in the identification of the
underlying conformal field theory describing the wave functions. We obtain the
fusion rules, and explicitly give a conformal field theory description, for a
two-parameter family (k,r) of wave functions. These include the Laughlin,
Moore-Read and Read-Rezayi states when r=2. The `gaffnian' wave function is the
prototypical example for r>2, in which case the conformal field theory is
non-unitary.
