The monotypic genus Nidnurbia n. gen. is described. The genus belongs to the tribe Tanytarsini of the subfamily Chironominae. A redescription of N. capicola (Freeman, 1955) n. comb. from the Cape Province, South Africa, is presented. The species was described as a member of the genus Micropsectra Kieffer, 1909 by Freeman. A study of the type material revealed that it is not closely related to Micropsectra. This fact is of zoogeographical interest because it drastically alters the concept of Micropsectra distribution. It is found, when N. capicola is excluded, that Micropsectra displays a Holarctic distributional pattern. The great majority of species occur in this region. Only a small number transgress into the Oriental region. No species has been reported from the Neotropical and Australian regions.