Fig. 1. An umbilical architecture dominated by funnel: Dictyokathina simplex Smout, megalospheric specimens from Qatar, Paleocene. Transmitted light micrographs. A: subaxial section showing funnels in their longitudinal extension. B: transverse section near the axis of the shell with the positions of sections A & C-D indicated. C-E: sections more or less perpendicular to the axis of the shell showing the vast umbilical area crowded with funnels. Note the chamber arrangement in multiple spirals, The start of supplementary spirals is indicated by arrows. The material does not allow resolution of the question: is the first chamber of a supplementary spiral fed from a foramen or from a canal? ch: chamber lumen; f: foramen; fu: funnel (vertical canal); isp: intraseptal interlocular space; ssp: spiral interlocular space; up: umbilical plate; (Hottinger, 2006; fig. 55  CC/BY-NC-SA)
- according to Hottinger (2006):
FUNNEL - (vertical canal); a tubular (interlocular) space more or less normal to the test surface produced by secondary lamination over several whorls. Funnels originate from the margins of sutural canals or fossettes, or of foliar apertures communicating with a spiral-umbilical canal. Vertical canals persist in secondarily laminated parts of the test as long as they are not covered by later chambers.
Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744
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