Order in. Sirenia. Sirenians. 



The Sirenians are mammals constituted especially for an aquatic 

 life, and formerly were confounded with the Cetaceans, with which, 

 however, they have no relationship. Like the members of the Order 

 CETACEA, the Sirenians have no hind limbs, and those on the forward 

 part of the body have been transformed into paddles, and the tail 

 has been expanded into a flattened rudder. 



The head is of the ordinary mammal type, being small for the 

 body, with a rounded superior outline, but the nostrils are provided 

 with flaps that open and close at the will of the animal. There are 

 no fins. The eye is small, and the ear has no external conch. Thick 

 lips, provided with a number of bristly hairs, cover the small mouth, 

 and the skin of the body is thick, with sometimes hair distributed 

 sparsely over it. The female has two pectoral mammae. Teeth are 

 entirely absent in some species, like Steller's Sea-Cow, but others 

 have both incisors and molars. The bones of the skeleton are 

 massive and dense, the skull being remarkable in this respect. Collar 

 and nasal bones are absent and there is no sacrum, but the pelvis 

 is represented by a pair of small bones. The two bones of the fore- 

 arm are usually ankylosed at the extremities, and the digits are five 

 in number. The lungs extend backward nearly to the last rib and 

 are very narrow. Rough, horny plates cover the symphysis of the 

 mandible, and the surface of the tongue is similar to these plates. 



Three species of Manatee are included in the family, one of which, 

 Steller's Sea-Cow (Hydrodamalis gigas}, is now extinct. This animal, 

 the largest of all, was from twenty to twenty-eight feet in length, 

 and at the time when Steller visited Bering Sea in 1741, was very 

 numerous around Bering and Copper Islands. The flesh, unfortu- 

 nately, was found to be highly palatable, far superior to salt pork, 

 and the sailors slaughtered the inoffensive beasts, until the last one 

 was killed in 1768. No skin has been preserved, and a collection of 

 bones in St. Petersburg and Washington alone remain to show what 

 kind of animal it was. Two living species of Manatee remain in the 

 New World, one, T. manatus, in southern North America; the 

 other, T. iniinguis, restricted to the rivers Amazon and Orinoco, in 

 South America. In the Old World, one, T. senegalensis , is confined 

 to West Africa in the district comprised between io-i6 latitude, 

 and 2o-27 longitude. East Africa, Australia, Ceylon, and islands in 

 the Bay of Bengal, the Indo-Malay Archipelago and the Philippines 

 possess the Dugong, more a marine animal than the Manatee, which 



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