  Annihilation cross sections of antiprotons and antineutrons on the proton
between 50 and 400 MeV/c show Coulomb focusing below 200 MeV/c and almost no
charge-dependence above 200 MeV/c. Similar comparisons for heavier targets are
not possible for lack of overlap between nuclear targets studied with $\bar p$
and $\bar n$ beams. Interpolating between $\bar p$-nucleus annihilation cross
sections with the help of an optical potential to compare with $\bar n$-nucleus
annihilation cross sections reveal unexpected features of Coulomb interactions
in the latter. Direct comparisons between $\bar n$-nucleus and $\bar p$-nucleus
annihilations at very low energies could be possible if $\bar p$ cross sections
are measured on the same targets and at the same energies as the available
cross sections for $\bar n$. Such measurements may be feasible in the
foreseeable future.
