Ctenoceras Noetling, 1884

Diagnosis. Slightly cyrtoconic, slightly compressed shell, with prominent sinuous, irregularly spaced annulation, growth lines, and fine longitudinal costules. Body chamber with two impressions at the concave parts of the flanks andone at the convex side. Siphuncle subcentral toward the convex side of the shell, nearly tubular with orthochoanitic septal necks. No endosiphuncular and cameral deposits known.