Fig. 1. Fossette, parafossette, ponticulus and retral process in advanced elphidiids from the Gulf of Aqaba, Red Sea. Recent. SEM graphs except D and H. A-F: Elphidium striatopunctatum (Fichtel et Moll). A: lateral (umbilical) view of the surface of the shell. B: detail showing the orifices of the canal system. Note the heavy spiking of the orifices, a device to fend off inedible particles such as diatom frustules. C: the detail of an orifice of a parafossette. Note its alignment with the axis of the adjacent ponticulus. D: axial section of megalosperic specimen, transmitted light micrograph. Note the row of foramina at the base of the chamber and the row of retral processes in the chamber roof. E: epoxy resin cast of the cavities of the shell showing the narrow spiral of the umbilical canal and the double row of fossettes and parafossettes representing the septal interlocular space. F: detail of a cast showing the disposition of fossettes and parafossettes and their connection to the intraseptal canal system. G-L: Elphidium craticulatum (Fichtel et Moll). G: oblique-peripheral view of entire shell. H: axial section of megalospheric specimen. Transmitted light micrograph. Note the single row of foramina at the bottom of the chamber and the broad umbilical pile with its funnels. I: apertural face showing the masked apertures. Note the imperforate keel, an important specific character. J: detail of G: the orifices of the fossettes in the last chamber alternate with tiny parafossettes. These disappear when they are covered by subsequent secondary lamellation in later stages of growth. K: epoxy resin cast showing umbilical cavities including the foliar chamberlets at the tips of the alar prolongation of the chamber. The foliar chamberlets are transformed during ontogeny into a spiral umbilical canal. L: epoxy resin cast showing detail of septal architecure: the alternation of retral processes and fossettes. Note the tiny pores on the cast of the main chamber lumen and the traces of the spikes on the walls of a fossette. a: aperture; af: apertural face; f: foramen; fo: folium; foa: foliar aperture; foc: foliar chamberlet; fs: fossette; k: keel; m: mask; mc: main chamber lumen; pfs: parafossette; po: ponticulus; rp: retral process; s: septum; suc: spiral umbilical canal; upil: umbilical pile; vc: vertical canal (funnel). Scale bars: 0.1 mm, double scale bars: 0.05 mm; (Hottinger, 2006; fig. 54) CC/BY-NC-SA)
- according to Hottinger (2006):
RETRAL PROCESSES - finger-like proximally directed extensions of the chamber lumen covered by ponticuli present at the margins of an intraseptal interlocular space.
Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744.
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