Constraints on Ho from the central velocity dispersions of lens galaxies

We employ Schwarzschild's method of the orbit modeling to constrain the mass profiles of the central lens galaxies in Q0957 + 561 and PG 1115 + 080. We combine the measured, central projected stellar velocity dispersions of these galaxies with the self-similar radial profiles of the rms velocity and of the Gauss Hermite moment h(4) observed in nearby galaxies for 0 less than or similar to R less than or similar to 2R(eff). For Q0957+561, we find a 16% uncertainty in the galaxy mass and formal 2 sigma Limits on the Hubble constant of H-o = 61(-15)(+13) km s(-1) Mpc(-1). For PG 115 + 080,we find that none of the viable lens models can be ruled out, so that H-o is not yet strongly constrained by this system.