▁shell ▁is ▁fus iform . ▁It ▁contains ▁ 7 ▁wh or ls , ▁of ▁which ▁ 1 ½ ▁ ▁compose ▁a ▁small , ▁smooth , ▁hel ico id ▁proto con ch . ▁Its ▁colour ▁is ▁white , ▁orn ament ed ▁with ▁four ▁to ▁six ▁pale ▁orange ▁bands , ▁appearing ▁only ▁in ▁the ▁inter st ices , ▁not ▁on ▁the ▁rib s . ▁These ▁sometimes ▁co ales ce ▁from ▁above ▁and ▁below , ▁thus ▁replacing ▁spir al ▁by ▁radial ▁painting . ▁The ▁radial ▁rib s ▁are ▁well ▁developed , ▁project ing ▁as ▁an ▁angle ▁on ▁the ▁shoulder , ▁continu ing ▁from ▁s uture ▁to ▁base , ▁and ▁amount ing ▁to ▁ten ▁on ▁the ▁body ▁wh or l . ▁The ▁spir al ▁threads ▁are ▁sharp ▁on ▁the ▁upper ▁wh or ls , ▁where ▁they ▁are ▁dec uss ated ▁by ▁radial ▁st ria e . ▁Grad ually ▁they ▁van ish , ▁till ▁on ▁the ▁middle ▁of ▁the ▁body ▁wh or l ▁the ▁surface ▁seems ▁smooth ▁to ▁the ▁eye , ▁and ▁only ▁a ▁few ▁eng ra ved ▁spir als ▁can ▁be ▁found ▁with ▁a ▁l ens . ▁The ▁mouth ▁of ▁the ▁a pert ure ▁is ▁linear . ▁The ▁slight ▁var ix ▁en clos es ▁a ▁small ▁sin us , ▁and ▁extends ▁in ▁a ▁narrow ▁free ▁edge . ▁The ▁inner ▁lip ▁is ▁well ▁developed , ▁with ▁fifteen ▁cross - bars . ▁B ene ath ▁the ▁var ix ▁are ▁four teen ▁short ▁entering ▁p lic ae . ▁ ▁Distribution ▁This ▁marine ▁species ▁occurs ▁off ▁Australia ▁( Que ens land