File:EB1911 Foraminifera - Perforata.jpg

English: 1, Spiral arrangement of simple chambers of a Reticularian shell, as in small Rotalia. 2, Ditto, with double septal walls, and supplemental shell-substance (shaded), as in large Rotalia. 3, Diagram to show the mode in which successively-formed chambers may completely embrace their predecessors, as in Frondicularia. 4, Diagram of a simple straight series of non-embracing chambers, as in Nodosaria. 5, Hastigerina murrayi, Wyv. Thomson, a, Bubbly (vacuolated) protoplasm, enclosing b, the perforated Globigerina-like shell (conf. central capsule of Radiolaria). From the peripheral protoplasm project, not only fine pseudopodia, but hollow spines of calcareous matter, which are set on the shell, and have an axis of active protoplasm. Pelagic; drawn in the living state. 6, Globigerina bulloides, d’Orb., showing the punctiform perforations of the shell and the main aperture. 7, Fragment of the shell of Globigerina, seen from within, and highly magnified, a, Fine perforations in the inner shell substances; b, outer (secondary) shell substance. Two coarser perforations are seen in section, and one lying among the smaller. 8, Orbulina universa, d’Orb. Pelagic example, with adherent radiating calcareous spines (hollow), and internally a small Globigerina shell. It is probably a developmental phase of Globigerina, a, Orbulina shell; b, Globigerina shell. 9, Polytrema miniaceum, Lin.; × 12. Mediterranean. Example of a branched adherent calcareous perforate Recticularian. 10, Calcarina spengleri, Gmel.; × 10. Tertiary, Sicily. Shell dissected so as to show the spiral arrangement of the chambers, and the copious secondary shell substance. a², a³, a⁴, Chambers of three successive coils in section, showing the thin primary wall (finely tubulate) of each; b, perforate surfaces of the primary wall of four tiers of chambers, from which the secondary shell substance has been cleared away; c′, c′, secondary or intermediate shell substance in section, showing coarse canals; d, section of secondary shell substance at right angles to c′; e, tubercles of secondary shell substance on the surface; f, f, club-like processes of secondary shell substance.