Emended diagnosis. Slender, circular or slightly com-pressed orthocones with symmetrically curved septa andstraight transverse sutures. Sutures parallel to the annulationsin each groove of the annulations. Annulations regularlyspaced, with fine transverse ornament, or growth lines.Growth lines in some species festooned. In some specieslongitudinal ridges that may form nodes at the ridges of theannulations. Siphuncle subcentral in early growth stages, cen-tral in late growth stages, narrow, but expanded within thechambers. Septal necks short suborthochoanitic to achoanitic,in advanced forms short reticulate. Incipient annulosiphuncu-lar deposits, and mural cameral deposits are known.