Abstract
The original diagnosis of Pravifusus Witkowski, Lange-Bertalot & Metzeltin was based on a few light and electron micrographs but several important details for its precise identification were missing. A careful review of Giffen (1975) and his collection slide (BM 80508—Giffenn. 628) showed that Pravifusus occurs also in South Africa where it was described as Campylosira inane Giffen. Pravifusus description is emended with more ultrastractural details provided by light, scanning and transmission electron microscopic observations of Brazilian and South African specimens. Its possible phylogenetic relationship with other closely related genera as Porannulus Hamilton & Poulin is discussed.