In zoology, any marine snail of the family Littorinidae, found on the shores of Europe and eastern North America. Periwinkles have a conical spiral shell, and feed on algae.
White was added to the flag to identify Bahrain as a friendly state. Red was the traditional colour of the Kharijite Sect. In 2002 the number of serrations were reduced to five, possibly representing the five pillars of Islam. Effective date: 19 August 1972.