Coccolithaceae
Coccolithus Schwarz, 1894
Coccolithaceae Kamptner, 1928
In plan view, the distal shield and the upper layer of the proximal shield remain in constant extinction, indicating a vertical optic axis relative to the microscope stage. In contrast, the lower layer of the proximal shield and the tube cycle, a permanent part of the structure, exhibit inclined extinction and length-fast (–) elongation.
Circular to elliptical placoliths composed of a distal shield, a double-layered proximal shield, and a single tube cycle surrounding a central area spanned by a variety of structures (e.g. cross, bar, mesh or grill). Varol (2023) demonstrated, using a mobile mount and a broken specimen, that the locking cycle holds all these elements in position.
Poche, F. 1913. Das System der Protozoa. Archiv für Protistenkunde. 30: 125-321.
Schwarz, E. H. L. 1894. Coccoliths. Annals and Magazine of Natural History 14: 341-346.
