  The properties of pentaquarks containing a heavy anti-quark and strange
quarks are studied in the bound state picture. In the flavor SU(3) limit, there
are many pentaquark states with the same binding energy. When the SU(3)
symmetry breaking effects are included, however, three states become
particularly stable due to a ``Gell-Mann--Okubo mechanism''. They are the $\bar
Qsuud$ and $\bar Qsudd$ states discussed by Lipkin, and a a previously
unstudied $\bar Qssud$ state. These states will have $J^P={1\over2}^+$ and
their masses are estimated. These states, if exist, may be seen in experiments
in the near future.
