(Borsetti & Cati 1976) Heimdal 1982 [Sphaerocalyptra]
Calyptrosphaeraceae (this is an artificial grouping -heterococcolith phase is currently un-confirmed)
Kleijne (1991) p. 69, pl. XVIII.
DescriptionAfter Young et al. 2003. Liths are semi-solids disks formed of three or four well-separated concentric rings of crystallites and low transverse ridge. BCs flat topped with node or ridge on distal surface, rather than true bridge. CFCs similar with transverse bridge or leaf.
DistributionTropical (Findlay & Giraudeau, 2000).