Fig. 2

Heterococcolith and holococcolith forms: (a) Calcidiscus leptoporus; (b) Umbilicosphaera hulburtiana; (c-g) Emiliania huxleyi, showing five different morphotypes (c, supercalcified; d, over-calcified; e, type A; f, type B; g; type C); (h) Gephyrocapsa ericsonii; (i) Gephyrocapsa muelerae; (j) Gephyrocapsa oceanica; (k) Gephyrocapsa ornata; (l) Coccolith of G. ornata; (m) Reticulofenestra parvula; (n) Reticulofenestra parvula var. tecticentrum; (o) Calciosolenia brasiliensis; (p) Calciosolenia murrayi; (q) Acanthoica quattrrospina; (r) Algirosphaera robusta; (s) Anacanthoica acanthos; (t) Cyrtosphaera aculeata. Scale bars: a-n and q-t, 1 μm; o-p, 10 μm