Fig. 1

Sections through rostroconchs, perhaps Filicardia inflata (M’Coy), in the Rapenburg, Leiden, the Netherlands. a Rapenburg 12. Oblique section through a shell. Structures on inside of shell to left are internal ribs (Pojeta 1987, fig. 14.77D). b-f Rapenburg 28, Rijksmuseum van Oudheden. b, e, f Antero-posterior sections (compare with Pojeta 1987, figs 14.69A, 14.75M; Fig. 2 herein). c Oblique section showing strong internal ribs (contrast with a). d Oblique section through a shell. Most possibly, all images with anterior oriented towards top of the page. All scale bars represent 10 mm