▁ ▁Description ▁The ▁size ▁of ▁the ▁shell ▁var ies ▁between ▁ 1 6   mm ▁and ▁ 3 1   mm . ▁The ▁rather ▁solid ▁shell ▁has ▁a ▁con ical ▁shape . ▁The ▁a pe x ▁is ▁obt use . ▁The ▁shell ▁is ▁prof ound ly ▁um bil ic ated . ▁Its ▁color ▁is ▁white , ▁orn ament ed ▁with ▁ob lique ▁black ▁fl amm ules . ▁The ▁six ▁wh or ls ▁show ▁a ▁cor onal ▁series ▁of ▁t uber cles . ▁They ▁are ▁car in ated ▁with ▁a ▁nod ul ose ▁car ina . ▁They ▁are ▁channel led ▁below ▁the ▁car ina , ▁and ▁spir ally ▁b ist ri ate . ▁The ▁body ▁wh or l ▁is ▁b ic ar inate . ▁The ▁base ▁of ▁the ▁shell ▁is ▁concentr ically ▁sul c ate . ▁The ▁a pert ure ▁is ▁sub r hom bo id , ▁with ▁its ▁upper ▁part ▁smooth . ▁The ▁col um ella ▁is ▁ar cu ate ; ▁termin ating ▁in ▁two ▁teeth . ▁ ▁Character istics ▁of ▁this ▁species ▁are : ▁the ▁wh or ls ▁are ▁divided ▁by ▁a ▁nod ose ▁ke el ▁into ▁a ▁larger ▁convex ▁upper ▁portion ▁and ▁a ▁smaller ▁channel led ▁lower ▁part . ▁A ▁second ▁series ▁of ▁bl unt ▁t uber cles ▁ad orn s ▁the ▁upper ▁edge ▁of ▁the ▁wh or ls ▁along ▁the ▁s uture . ▁ ▁Below ▁there ▁are ▁slightly ▁elev ated ▁st ria e . ▁The ▁body ▁wh or l ▁has ▁the ▁base ▁sharp ly ▁separated ▁by ▁a ▁second ▁ke el