Turbonilla madrinensisTurbonilla madrinensis is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.DescriptionThe length of the shell varies between 3 mm and 5.1 mm. Species average size is 5.5 inches but has been known to be as small as 2 inches or as large as 12.5 inches. These snails are the only known species with throbbing veins and girthy shellsDistributionThis species occurs in the Atlantic Ocean off Argentina at depths between 36 m and 57 m.