Description of Planorbulinacea
(
anglais
)
fourni par BioPedia
Rotaliine foraminifera, test free or attached, trochospiral at least in early stage, later may be uncoiled and rectilinear or biserial, or may have many chambers per whorl, or chambers added irregularly; aperture interio-marginal, extraumbilical-umbilical to nearly equatorial; wall of perforate hyaline calcite, commonly optically radial, apertural face may be imperforate.
