Lagoon Island

or ATOLL. (Phys. Geog.) A ring formed by coral-zoöphytes in the ocean, enclosing a tract of smooth water. They abound in the Pacific and Indian oceans. The ring is usually elevated into land formed of sand, on which palms sometimes grow. It is often more or le incomplete, and sometimes it consists of a great number of separate little atolls. The water usually breaks furiously upon the outer side of atolls. They vary in size, some being le than a mile in diameter, while the Suadiva atoll is 44 geographical m. in one direction and 34 in another,and Rimsky atoll is 54 m. by 20. [s. 523]