Diagnosis. Slender, circular or slightly compressed orthocones with asymmetrically curved septa and straight transverse or slightly oblique sutures. Sutures parallel, or nearly so, to the annulations. Annulations slightly irregularly spaced, with fine transverse ornament. Siphuncle eccentric, narrow, tubular or slightly expanded within the chambers. Septal necks orthochoanitic. Cameral and endosiphuncular deposits not known.