Fig. 37 in Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities

Fig. 37. Longitudinal cross sections of protocycloceratid cephalopods from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A–B. Protocycloceras lamarcki (Billings, 1859). A. Specimen FMNH-P30418, approximal dorso-ventral median section with details of heavily recrystallized siphuncle and sepal necks, showing concave siphuncular segments. B. Specimen FMNH-30409, apical fragment of phragmocone with cameral deposits and siphuncle with concave segments and orthochoanitic septal necks. C. Protocycloceras minor sp. nov., FMNH-P30411, holotype, with poorly preserved details; siphuncle with nearly tubular segments and probably short orthochoanitic septal necks. Scale bar = 2 mm for all figures.