▁strength ened ▁with ▁longitud inal ▁sub ere ct ▁rounded ▁cost ae , ▁where of ▁there ▁are ▁ 1 2 ▁on ▁the ▁pen ult imate ▁wh or l ▁and ▁about ▁ 1 6 ▁on ▁the ▁body ▁wh or l ▁( th ose ▁towards ▁the ▁outer ▁lip ▁being ▁fin er ), ▁gradually ▁van ishing ▁a ▁little ▁below ▁the ▁middle . ▁Between ▁the ▁more ▁sl ender ▁rib s ▁there ▁are ▁a ▁few ▁fine ▁intermediate ▁ones , ▁but ▁this ▁may ▁only ▁be ▁an ▁individual ▁peculiar ity . ▁The ▁wh or ls ▁are ▁also ▁trans vers ely ▁l ir ate . ▁Li ra e ▁of ▁different ▁thick ness es , ▁numerous , ▁raised ▁equally ▁between ▁and ▁upon ▁the ▁cost ae , ▁fewer ▁and ▁co ar ser ▁upon ▁the ▁upper ▁wh or ls , ▁and ▁about ▁ 3 0 ▁on ▁the ▁body ▁wh or l . ▁The ▁a pert ure ▁is ▁rather ▁narrow , ▁less ▁than ▁half ▁the ▁length ▁of ▁the ▁shell , ▁exhib iting ▁the ▁same ▁band ed ▁colours ▁as ▁the ▁exterior . ▁The ▁outer ▁lip ▁is ▁thick ened ▁within ▁and ▁exterior ly , ▁thin ▁at ▁the ▁extreme ▁edge , ▁smooth ▁interior ly . ▁The ▁sin us ▁is ▁small ▁at ▁the ▁s uture . ▁The ▁col um ella ▁is ▁simple , ▁ob liqu ely ▁flex uous . ▁The ▁si ph onal ▁canal ▁is ▁a ▁trif le ▁ob lique ▁and ▁slightly ▁rec ur ved . ▁ ▁Distribution ▁This ▁marine ▁species ▁occurs ▁off ▁Japan ▁and ▁the ▁Philippines . ▁ ▁References ▁▁ ▁D unker , ▁Jap . ▁M oll ., ▁