  We report on the properties of new ruthenocuprates Ru(1-x)Sr2GdCu(2+x)O(8-y)
(x=0, 0.1, 0.2, 0.3, 0.4, 0.75) that extend the superconductivity found
previously in RuSr2GdCu2O8 (Tc=45 K) to the solid solution with varied Ru/Cu
ratios. The compounds have been synthesized in high-pressure oxygen atmosphere.
The maximum temperature of the superconducting transition is 72 K for the x=0.3
and 0.4 compositions. The reported behavior of magnetization at low
temperatures can be qualitatively explained assuming a quasi-two-dimensional
character of the superconducting regions in compounds studied.
