QO Vertebrata. 



while the manatee or mermaid is a native of the 

 opposite shores of the South Atlantic, extending from 

 South America to Africa. These are often confounded 

 with whales, but can be known therefrom by their 



FIG. 43. 



Heart of dugong, showing the separation of the ventricles. 



n, right auricle ; d, left auricle ; b, right ventricle ; e, left ventricle ; 

 f, aorta ; c, pulmonary artery. 



possessing a neck, a movable elbow-joint, a trace of 

 nails, and nostrils far forward and not at the top of 

 the head. They also, except the extinct Rhytina, 

 possess teeth. 



58. Order 6, Ungulata, includes all those herbi- 

 vorous mammals whose extremities are used solely as 

 organs of progression, and not of prehension, and in 

 which each toe ends in a hoof or broad case of horny 

 epidermis. They are usually animals of large size, 

 and they have no collar-bones. Their brains, however, 

 are small in proportion to the bulk of the body, and 



