1994  Pennoceras sp.nov. Boardman, Work, Mapes & Barrick: 62, pl.3 fig.6-8,
?   -----    ? Pennoceras sp.nov. Boardman, Work, Mapes & Barrick: 62, pl.3 fig.12-14.
     2003  Pennoceras ? n.sp.  Work & Boardman, p.1195.

No.SUI 55433, Iowa City, ? SUI 55436, Iowa City.