The Pioneer Venus Orbiter Ultraviolet Spectrometer sees variable disk brightness features similar to the well-known ''UV markings'' seen at longer wavelengths. The bright features are consistent with a homogeneous cloud of H2SO4 aerosols. The darker features show the presence of a broad-band absorber, which is at some depth in the cloud layer. Additonal contrast arises from SO2 absorption as a function of wavelength rules out a uniform mixing ratio for the SO2. The data are well fitted by an inhomogeneous light scattering model in which the SO2 scale height is one-fifth the CO2 at 40 mb is 1¿10-7. A model of the oxidation of sulfur dioxide in the upper cloud reproduces the observed vertical distribution of SO 2 and indicates that SO2 alone is sufficient to produce the observed amount of H2SO 4 in this region.