http://www.sciencedirect.com/science/article/pii/S1055790317303093

Trachylepis varia has been split into three species, varia remains in South Africa and extends northward into Mozambique and parts of Zimbabwe, laevigata is resticted to the Waterberg Massif in South Africa and damarana from northern South Africa, Zimbabwe, Botswana and Namibia.
Species level clades are found northwards of the Zambezi/Kunene Rivers, but have not been described.

Weinell, J. L., & Bauer, A. M. (2017). Systematics and phylogeography of the widely distributed African skink Trachylepis varia species complex. Molecular Phylogenetics and Evolution.

Morphological diagnostics (quoted from above paper):
T. damarana "can usually be distinguished from T. varia by having a relatively longer second loreal scale"
"Trachylepis laevigata has thin, dark longitudinal stripes between each of the medial six dorsal scale rows and these stripes begin within a few scales rows behind the nuchal scales, whereas in T. damarana, the first 10 dorsal scale rows behind the nuchal scales are uniformly colored and of the same color as the dorsal surface of the head"