  We review various prescriptions which have been proposed for the turbulent
transport of matter and angular momentum in differentially rotating stellar
radiation zones. A new prescription is presented for the horizontal transport
associated with the anisotropic shear turbulence which is produced by the
differential rotation in latitude; this `beta-viscosity' is drawn from torque
measurements in the classical Couette-Taylor experiment (Richard & Zahn 1999).
Its implementation in a stellar evolution code leads to enhanced mixing, as
illustrated by models of a rotating main-sequence star of 1.5 solar mass.
