We report on an investigation of superconductivity and magnetism in the series of compounds M(Formula presented)Pb (M=rare earth, Th, U) through measurements of electrical resistivity, magnetic susceptibility, specific heat, and lattice parameters. Both single crystals and polycrystalline samples were studied. The compound (Formula presented)Pb was examined for possible heavy-fermion behavior, and found to exhibit antiferromagnetic order below T=35 K. © 1996 The American Physical Society.