  The JYFLTRAP double Penning trap at the Ion Guide Isotope Separator On-Line
(IGISOL) facility has been used to measure the atomic masses of 13 neutron-rich
rare-earth isotopes. Eight of the nuclides, $^{161}$Pm, $^{163}$Sm,
$^{164,165}$Eu, $^{167}$Gd, and $^{165,167,168}$Tb, were measured for the first
time. The systematics of the mass surface has been studied via one- and
two-neutron separation energies as well as neutron pairing-gap and shell-gap
energies. The proton-neutron pairing strength has also been investigated. The
impact of the new mass values on the astrophysical rapid neutron capture
process has been studied. The calculated abundance distribution results in a
better agreement with the solar abundance pattern near the top of the
rare-earth abundance peak at around $A\approx165$.
