  We report ac susceptibility measurements on polycrystalline samples of
SrRuO_3 and three ruthenocuprates: superconducting RuSr_2GdCu_2O_8 (Ru-1212),
superconducting RuSr_2Eu_(2-x)Ce_xCu_2O_y (Ru-1222, x=0.5) and
nonsuperconducting, insulating RuSr_2Eu_(2-x)Ce_xCu_2O_z (Ru-1222, x=1.0). Ac
susceptibility of both Ru-1222 compositions exhibit logarithmic time relaxation
and `inverted' hysteresis loops. Ru-1212 samples exhibit none of these
behaviors. We interpret the magnetic behavior of Ru-1222 in the framework of
weakly coupled magnetic multilayers and argue that superconductivity coexists
with qualitatively different magnetic behaviors.
