THE sirenians are large, aquatic mammals, somewhat fish-like in form, entirely confined to the shores of seas in hot countries. The order owes its name to the fact that it is thought the belief in mermaids may have originated through some traveller seeing some such creatures as these. One family, the manatees, are sluggish, awkward animals of ten feet and over in length, feeding exclusively on seaweed and river plants.
The dugongs are very similar, except for the fact that they are perhaps more strictly marine in their habits and sometimes attain a larger growth. They are found on the coast of the Indian Ocean, extending in range to the north coast of Australia.