Senegalinium acuminatum (Cookson and Eisenack, 1958) Loeblich Jr. and Tappan, 1977

Now Isabelidinium. Originally Deflandrea, subsequently Senegalinium, thirdly (and now) Isabelidinium; see also Alterbia (combination illegitimate). Lentin and Williams, 1981 retained this species in Alterbia Lentin and Williams, 1976.

Holotype: Cookson and Eisenack, 1958, pl. 4, fig.5
Paratype: Cookson and Eisenack, 1958
Locus typicus: Carnarvon Basin, W-Australia
Stratum typicum: Cenomanian

Original descripition: Cookson and Eisenack, 1958, p. 27: Deflandrea acuminata
Theca broadly oval with convex sides or almost sphaerical, apex acuminate, antapex obliquely truncate, prolonged on one side into a small pointed horn. A transverse girdle is percepible at the lateral margins of the theca. The capsule, which is always seperated from the membrane of the theca by a relatively wide space is approximately sphaerical, and slightly pointed on the side directed towards the apex of the theca. Both the internal and external membranes are smooth. A rounded or polygonal pylome is present above the apex of the capsule.
Dimensions: Range - theca 66-99 x 52-62 µm; capsule 38-47 x 38-47 µm.