Palaeogene triserial planktonic foraminifera

Triserial planktonic foraminiferal species from the Palaeogene are classified into the Early Danian Guembelitria, with pore mounds on the test surface, and the Early Eocene-Late Oligocene Jenkinsina, which are also microperforate but lack pore mounds. The stratigraphic and palaeogeographic ranges are discussed, the holotype of G. cretacea Cushman (the type species of Guembelitria ) is re-illustrated, and neotypes designated for G. danica (Hofker) and Jenkinsina triseriata (Terquem). Chiloguembelitria is shown to be a junior synonym of Guembelitria.