Fig. 17 in Taxonomy and ontogeny of the Lituitida (Cephalopoda) from Orthoceratite Limestone erratics (Middle Ordovician)

Fig. 17. Ancistroceras undulatum (Boll, 1857) from the Upper Grey Orthoceratite Limestone; specimen MB.C.11697a (Hoyers 1912 Coll.) from Skowarcz (former Schönwarling); previously figured by Foerste (1930: pl. 41 fig. 1); dorsal, lateral and ventral views. Note imprints of the vascular system near the apex visible in the photograph on the left. Scale bar units = 1 mm.