MANA'TUS, n. The sea-cow, or fish-tailed walrus,an animal of the genus Trichechus, which grows to an enormous size; sometimes it is said, to the length twenty three feet. Of this animal there are two varieties,the australis, or lamentin, and borealis, or whale-tailed manati. It has fore feet palmated,and furnished with claws, but the hind part ends in a tail like that of a fish. The skin is of a dark color,the eyes small, and instead of teeth, the mouth is furnished with hard bones, extending the whole length of the jaws.

[There are eight grinders on each side in each jaw.] It never leaves the water, but frequents the mouths of rivers, feeding on grass that grows in the water.