Annular passage

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Fig. 1. Embryonic apparatus. A: Discocyclina, stereograph after Ferràndez (1999), modified. Schema, not to scale; achl: auxilliary chamberlet; ast: annular stolon; ecr: equatorial crest; il: inner lamella; lchl: lateral chamberlet;ost: oblique stolon; ost(d): oblique stolon of deuteroconch; p: pore; pap: papilla; peri: periembryonal chamberlets; rst: radial stolon; rst(d): radial stolon of deuteroconch; deuteroconch);(from Hottinger, 1977); (Hottinger, 2006; fig. 5 [1] CC/BY-NC-SA)


Definition

  • according to Hottinger (2006):

ANNULAR PASSAGE - (annular stolon); annular, open space in preseptal position, may be single, in the equatorial plane, as in Sorites, or double, in lateral position, as in the archaiasines. In orbitoidiform foraminifera the adjacent lumina of a chamberlet cycle may be connected by a pair of tubiform lateral passages in postseptal position (lateral annular stolons, as in Discocyclina) or by several layers of annular stolons ("six-stolon system" as in advanced Eulepidina). See also: preseptal passage.


See also:

References

Ferràndez I Cañadell (1999), Morfoestructura i paleobiologia dels Ortofragmínidos de la Mesogea (Discocyclinidae i Orbitocyclinidae, Foraminifera), Arxius de les Seccions de Ciències, Barcelona, (Secció de Ciències i Tecnologia), CXXI, 339 p.

Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744

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