ORDERS OF MAMMALIA. 319 
Ant-eaters, of which the best known is the great Ant-eater 
(Myrmecophaga jubata). The body in this family is covered 
with hair, the tail is long, and the teeth are altogether wanting. 
They feed chiefly upon ants and termites, which they catch by 
protruding their long and sticky tongues, having previously 
broken into the nest by means of their strong curved claws. 
The Edentata are represented in the Old World by only two 
genera. One of these is the genus JZanzs, comprising the scaly 
Ant-eaters or Pangolins, which are exclusively confined to Asia 
and Africa. In these singular animals the body and tail are 
covered by a flexible armour, composed of horny plates or scales 
overlapping like the tiles of a roof. The other genus is Oryc- 
teropus, comprising only the so-called Ground Hog of South 
Africa ; which also lives upon insects, and burrows by means 
of its strong digging-claws. 
As regards the geographical distribution cf the Edezzaza, it 
is to be remembered that the order has a very limited range at 
the present day. The true Ant-eaters, the Armadilloes, and the 
Sloths, are exclusively confined to South America, in which 
country a group of gigantic ‘extinct Edentates existed in the 
later portion of the Tertiary epoch. The scaly Ant-eater is 
common to Asia and Africa; and the Ground Hog is confined 
to South Africa. 
ORDER IV. SIRENIA.— This order comprises only certain large 
marine Mammals, known as Dugongs and Manatees, which 
were long classed with the Whales and Dolphins (Cedacea). 
They agree with the Whales in the adaptation of the body to 
an aquatic life, especially in the facts that the anterior limbs are 
converted into swimming-paddles, the hind-limbs are wholly 
wanting, and the hinder end of the body forms a powerful 
caudal fin, which is placed so as to strike the water horizontally 
and not vertically, as in Fishes. They differ from the Cetacea 
in having the nostrils placed at the anterior part of the head, 
and in having molar teeth with flat crowns, adapted for a 
vegetable diet. Fleshy lips are present, the upper one usually 
with a moustache, and the skin is covered with scanty bristles. 
The head is not disproportionately large as compared with the 
body, and there is a tolerably distinct neck. They are vegetable 
eaters, feeding chiefly upon seaweeds, and haunting the mouths 
of rivers and estuaries. 
