Ellipsagelosphaera frequens Christmas, 1965
The elliptical placolith includes single-tiered distal and proximal shields, a double tube cycle and a central area spanned by disjunct traverse bar structures. All components except the outer tube cycle exhibit inclined extinction lines and length-fast (-) elongation in the plan view. The outer tube cycle displays constant extinction because the optic and c-axis are vertical relative to the microscope stage in the plan view. The extinction line angle is about 67° on the distal shield, but it can not be measured in the tube cycle due to the oblique orientation of the tube cycle segments.
Ellipsagelosphaera differs from Watznaueria in its open central area with a disjunct traverse bar, whereas the latter has a closed or open central area without any bar or cross structure.
Noël, D. 1965. Sur les Coccolithes du Jurassique Européen et d'Afrique du Nord. Essai de classification des coccolithes fossiles. Éditions du Centre National de la Recherche Scientifique, Paris. 1-129.