/ 98 09 06 3 v 1 5 S ep 1 99 8 Redshifts of the Gravitational Lenses MG 0414 + 0534 and MG 0751 + 2716

We report redshifts in two gravitational lens systems, MG 0414+0534 and MG 0751+2716. The lens galaxy in MG 0414+0534 lies at zl = 0.9584± 0.0002. The luminosity and extreme red color of the lens are then typical of a passively evolving, early-type, ∼ 2L∗ galaxy. The galaxy cannot have a significant global mean extinction without being anomalously luminous. The lens galaxy in MG 0751+2716 has a redshift of zl = 0.3502 ± 0.0003 and it is a member of a small group. The group includes the nearby, bright companion galaxy whose redshift we confirmed to be z = 0.3501 ± 0.0001 and a nearby emission line galaxy with z = 0.3505 ± 0.0003. A second emission line galaxy with z = 0.5216 ± 0.0001 was found nearly superposed on the first emission line galaxy. The source in MG 0751+2716 is a zs = 3.200± 0.001 radio quasar. For flat universes with Ω0 = 1.0 (0.3), 96% (87%) of lenses like MG 0414+0534 and 7% (3%) of lenses like MG 0751+2716 are expected to have lower lens redshifts than observed. Subject headings: cosmology — distance scale — gravitational lensing — quasars: individual (MG 0414+0435, MG 0751+2716) Based on observations at the W. M. Keck Observatory, which is operated jointly by the California Institute of Technology and the University of California