Figure 70: Odd association and polar structures in Praealveolina tenuis Reichel. From Alcantara, Lisbon; Cenomanian. Transmitted light micrographs.
A: microspheric specimen, axial section; B: megalospheric specimen, axial section; C-E: odd partners: C: axial section of microspheric Simplalveolina sp.; D: axial sections of megalospheric Simplalveolina sp.; E: Ovalveolina sp, axial section. F: microspheric P. tenuis, axial section, detail showing polar structure with floors and shaftsin the basement. G: model of two subsequent chambers near their polar ends where the first floors in the basement appear. H: model of the protoplasmic body filling the cavities in G. Both models schematic, not to scale, after Reichel, 1933.
a: aperture: af: apertural face; bchl: basement chamberlets; bl: basal layer; chl: (main) chamberlets; fl: floor; prp: preseptal passage; rp: (incipient) residual pillar; s: septum; sa: supplementary aperture; sh: shaft; sl: septulum; sut: cameral suture.