cf. 1938  Manticoceras clarkei Miller, p.80, pl.14 fig.15-17.
 cf. 1965  Aulatornoceras clarkei.-House, p.121, pl.11 fig.122-
           123.
     1993  Polonoceras cf. clarkei.-Becker: 227, pl.11 fig.3-
           5, textfig.77o.