  We show here the separability of Hamilton-Jacobi equation for a hierarchy of
integrable Hamiltonian systems obtained from the constrained flows of the
Jaulent-Miodek hierarchy. The classical Poisson structure for these Hamiltonian
systems is constructed. The associated $r$-matrices depend not only on the
spectral parameters, but also on the dynamical variables and, for consistency,
have to obey the classical Yang-Baxter equations of dynamical type. Some new
solutions of classical dynamical Yang-Baxter equations are presented. Thus
these integrable systems provide examples both for the dynamical $r$-matrix and
for the separable Hamiltonian system not having a natural Hamiltonian form.
