igii AMMONITES SEMICELATUS 31c 



Comparable Species 



ArgonaiUa anguinus, Reinecke, 1818, fig. 73. 



Am. anmdatus, J. Sowerby, i8ig, ecu (fig. 5 is Oppel's lectotype). 



Am. tenuicostatus, Young & Bird, 1822, xn, 8. 



Am. cequistriatus, Miinster in Zieten, 1830, xii, 5. 



Am. annulatus ; d'Orbigny, 1844, Lxxvi, i, 2. 



Am. annulatus ; Quenstedt, 1849, xm> n- 



Stephanoceras anntdatum ; Wright, 1884, lxxxiv, 7, 8. 



Am. communis ; Quenstedt, 1885, XLVI, i, 2. 



Dactylioceras helianihoides, Yokoyama, 1904, iv, 4 — 6. 



