Knowledge of the distribution and flower associations of the monospecific genus Priscomasaris is expanded. The nature of the provision, nesting situation, nest structure, and method of nest construction are recorded for the first time. Priscomasaris namibiensis Gess has been encountered solely in the Mopane Savanna/ Northern Namib transition and Dwarf Shrub Savanna (of Giess 1971), all records falling within the northwestern extension of the Nama Karoo Biome (of Rutherford and Westfall 1986, as adapted by Lovegrove 1993). Flowers visited for nectar and pollen are of the families Aizoaceae (non-Mesembryanthema) and Molluginaceae. Nesting aggregations were located in sparsely vegetated areas of horizontally presented, stabilized, sandy soil. The nest is a multicellular burrow with its entrance surmounted by a mud-turret and with each excavated cell containing a constructed mud-cell. Water is used in excavation and construction. Evidence for bivoltinism is presented.