Polycyclolithus Forchheimer, 1968
Lithastrinaceae Thierstein, 1973
Eprolithaceae Black, 1973
Nannoliths have two vertical wall cycles and a central area that may be closed, vacant, or spanned by a left-handed imbricated diaphragm. Segments have tangential c-axis orientation.
Black, M., 1973. British Lower Cretaceous Coccoliths. I-Gault Clay (Part 2). Palaeontographical Society Monograph 127, 49-112.
Forchheimer, S., 1972. Scanning electron microscope studies of Cretaceous coccoliths from the Köpingsberg Borehole No. 1, SE Sweden. Sveriges Geologiska Undersökning, Series C. #668, 65, 1-141.
Thierstein, H. R., 1973. Lower cretaceous calcareous nannoplankton biostratigraphy. Abhandlungen der Geologischen Bundesanstalt. 29, 3-52.