Key to Species
of the Calvert Formation,
Calvert Cliffs, Maryland, USA
in material provided by Yasemin Tulu, John Nance and S. Godfrey from
Calvert Marine Museum
Spiral and apertural view of one specimen of Cribrononion sp.
The classification is based upon: C. W. Poag: Paynes Hammock (Lower Miocene?) foraminifera of Alabama and Mississippi in Micropaleontology, Oct 1966, Plate 7 Fig. 9/10