Fig. 10. A in Minute Silurian oncocerid nautiloids with unusual colour patterns

Fig. 10. A. Holotype of Pomerantsoceras pollux "var. castor" (Barrande, 1866). Specimen NM−L 571, in lateral (A1) and ventral (A2) views, and detail of the siphuncle (A3); Butovice Na Břekvici Section, Colonograptus colonus Zone, Gorstian, Ludlow. B. Holotype of Pomerantsoceras pollux (Barrande, 1866). Specimen NM−L 570, in lateral view showing diagenetic rupture of the shell (B1); and lateral (B2, B4) and ventral (B3) views. Malá Chuchle, Vyskočilka locality, Testograptus testis, Homerian, Wenlock. Specimens A1, A2, and B1 are coated with ammonium chloride. Scale bars 5 mm.