It has been established that the introduction of fibers not only increases the viscosity of the matrix (a Newtonian liquid), but also leads to dependence of the viscosity on the shearing stress a viscosity anomaly [1-3]. At certain concentrations of monodisperse fibers and with certain viscosities of the matrix, a viscosity "superanomaly" has appeared, in which the values of the first difference of the normal stresses in simple shear were negative [4]. It was found that this phenomenon also occurs in shear flow of lyotropic liquid crystals [5]. The suspensions studied in [I] contained uniform-length fibers (s = 54.3, = 1.25 mm). Here we are presenting results from an investigation of suspensions with a variation of fiber length from one suspension to another and also mixtures of such suspensions. According to [6], molecular composites containing rigid rodlike molecules in a matrix of flexible molecular coils can be considered, at the molecular level, as analogs of composites filled with macroscopic chopped fibers. A system of randomly positioned, rigid, rodlike macromolecules in a solvent was examined in [7]. Unit volume of such a suspension contains n rigid rods with length s and diameter d; the volume fraction of fibers C = ~ns ~. For a flowing liquid suspension, the following inequalities must be fulfilled: