Holococcolithophorids formed half of the total number of species of the 1985 summer coccolithophorid flora in surface waters of the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic. They showed highest frequencies under oligotrophic conditions.
Fifty-four taxa of holococcolithophorids were identified. They are illustrated by SEM-micrographs. Three new genera, Calicasphaera gen. nov., Poricalyptra gen. nov. and Poritectolithus gen. nov., with two new types of holococcoliths, calicaliths and fragarioliths, are described. The genus Anthosphaera Kamptner is emended. Eleven species and eight types in open nomenclature are new to science. One species is revised and new combinations are proposed for eight species, while new ranks are given to three holococcolith stages of species that may also bear heterococcoliths.
The holococcolith-bearing Calcidiscus leptoporus f.rigidus (Gaarder) stat. nov. and the heterococcolith-bearing Calcidiscus leptoporus (Murray and Blackman) Loeblich and Tappan f. leptoporus are two stages in the life cycle of one and the same species.
