GENERAL CHARACTERISTICS. 



21 



are different, we must confess that this asso- 

 ciation is not in harmony with the principles 

 that must be followed in a natural classifica- 

 tion. 



The sea-cows are large, peace-loving animals 

 which inhabit the gulfs and bays on the sea- 

 coast, and advance up the mouths of rivers 

 far into the interior of the land in order to 



seek their food, which consists solely of 

 vegetable substances — various alga; in the 

 sea, leaves, roots, and fleshy fruits in the 

 rivers. Only two living genera are now 

 known. A third, the Rhytina, which formerly 

 inhabited the shores of the Behring Sea and 

 other coasts of Eastern Siberia, has been 

 extinct since 1 768. Steller has left us a very 



Fig. 143. — Tlie Dugong (Halicore Dugong). 



valuable and complete description of this 

 animal, but that description unfortunately 

 was not accompanied by a drawing. Since 

 the year mentioned no living example of this 

 remarkable species has been seen, although, 

 indeed, in certain districts regular graveyards 

 of bones belonging to it have been dis- 

 covered. 



The Dugong [Halicore Dtigong), fig. 143, 

 inhabits the Indian Ocean and its bays, the 

 Red Sea, the Persian Gulf, &c., and extends 

 even to Australia. It is a large massive 

 animal, attaining the length of 16 or 17 feet. 

 The pretty thick body becomes rapidly 

 thinner towards the broad halfmoon- shaped 

 tail. The flippers are short and broad, and 

 without nails. The small head ends 



m a 



very thick upper lip, which is very blunt 

 below and behind, and incloses the swollen 

 ball-shaped lower lip. The skin, dark gray 

 on the back but lighter on the under surface, 

 is sparsely covered with short hair. The 

 eyes are pretty small, provided with a large 

 third eyelid or nictitating membrane, and 

 protected by a semicircle of stiff eyelashes 

 above. The hairs of the whiskers are strong 

 and short, almost spiny. 



The form of the jaws and the arrangement 

 of the teeth are very remarkable. The very 

 large premaxilla is bent downwards in an 

 adult animal at an angle of 60 degrees, and 

 in the male each half of it carries at its end 

 a strong straight tusk which gets worn away 

 obliquely and thus kept sharp by use. This 



