As part of a biodiversity survey in the arid western interior of South Africa, two new species of dionychan spiders were collected and are described herein. The prodidomid genus Namundra Platnick & Bird, 2007, previously known from arid parts of Namibia and Angola, is recorded from South Africa for the first time, and N. murphyi sp. n. is described from a single female. Scanning electron micrographs, based on juvenile specimens only, detail some aspects of the fine morphology of this enigmatic genus for the first time. A new species of the trochanteriid genus Platyoides O. Pickard-Cambridge, 1891, P. robertsi sp. n., is described from three females. DNA barcodes (cytochrome oxidase subunit I, COI) are provided for all of the specimens included in this paper.