Virtual thin sections of <i>Marginopora charlottensis</i> A-form (RGM.1325042).

A) Radial vertical thin section in the outer part of the shell. Arrows indicate the position of C-E. B) Virtual vertical thin sections perpendicular to A showing the relatively thick, parallel with no connections nor interruptions. C) Virtual horizontal section through the lateral chamberlets. D) Virtual horizontal section through the annular passage (ap). E) Virtual horizontal section through the marginoporid structure showing rare annular connections (ac) and the alternating directions of the stolon passage (rs). Scale bars 100 μm.