CETACEA. 



109 



and chiefly to the Andes, and are the American repre- 

 sentatives of the Camels. 



The Llama, or Guanaco, A. llacma, Linn., is about 

 the size of the Stag, and cov- Fig. &>. 



ered with coarse, chestnut- 

 colored hair. This species 

 was early domesticated and 

 extensively used as a beast 

 of burden, in which capacity 

 it is still employed. The Al- 

 paca is a variety with long, 

 woolly hair, which furnishes 

 material for the best of fab- 

 rics. 



The Paco or Vicuna, A. 

 vicunna, Linn., is of the size 

 of a sheep, and covered with fawn-colored wool, which is 

 also used in the manufacture of valuable fabrics. 



Remains of extinct Camelidae are found in the tertiary 

 rocks of Nebraska. 



Llama. 



SUB -SECTION XI. 



THE ORDER OF CETACEA, OR CETACEANS. 



THE Order of Cetacea comprises Mammalia which are 

 formed for an exclusive residence in the water. They 

 have no hind feet, two small bones suspended in the flesh 

 being the only vestiges of posterior extremities ; their an- 

 terior members closely resemble fins ; arid, excepting the 

 tail, which spreads horizontally, their general appear- 

 ance is decidedly fish-like. They are, however, genuine. 

 Mammals, have warm blood, respire by means of lungs, 

 come frequently to the surface of the water to take in 

 fresh supplies of air, though some can remain be- 

 neath the water for half an hour or more, and pro- 



