Description of Coccolithus

Coccolithophorids, with non-motile hetero-coccolith-bearing and motile holococcolith-bearing phases. Non-motile phase bearing placoliths, with both shields composed of overlapping wedge-shaped elements and the central area wide and open, motile phase with two flagella, haptonema bulbous, bearing crystalloliths, marine, planktonic, commonly found in boreal waters and less frequently along the coastlines of most continents (including Australasia and Africa).