  A one-relator surface group is the quotient of an orientable surface group by
the normal closure of a single relator. A Magnus subgroup is the fundamental
group of a suitable incompressible sub-surface. A number of results are proved
about the intersections of such subgroups and their conjugates, analogous to
results of Bagherzadeh, Brodskii, and Collins in classical one-relator group
theory.
