B.Leadbeater (Leadbeater, 1972a: 75, figs 1 (type), 47, 48)
Manton & Leadbeater (1974: 9, figs 24–42)
Cells ovoid, with a flattened flagellar pole and a slight central depression, 4 × 3.5 µm, biflagellate; body covered in unmineralised scales. Body scales of 2 types: outer layer of large flat elliptical rimless scales, patterned with radiating striae on proximal face, patternless on distal face; small plate scales forming an inner layer or positioned in interstices of larger plates, elliptical, 0.4 × 0.32 µm, concave with an inflexed rim, patterned as larger scales. Flagella 10–20 µm long. Haptonema c. 8 µm long.
Southern Ocean, south of Australia; Norway and Mediterranean and Adriatic Seas (Leadbeater, 1972b).
Chrysochromulina genus description: Cells have homodynamic flagella and a coiling haptonema, and electron microscopy is usually required to identify the species. As well as being photosynthetic, these fragile haptophytes ingest picoplanktonic and nanoplanktonic organisms by phagocytosis.