VERTEBRATA. 355 



into webbed paddles for swimming, the hinder ones being 

 bound in with the skin of the tail. Such are the Seals, 

 Walrus, and Eared Seals, or Sea-lions, b. Plantigrades, in 

 which the whole, or nearly the whole, of the hind-foot 

 forms a sole, and rests on the ground. The claws are not 

 retractile; the ears are small, and tail short. Bears, Bad- 

 gers, and Raccoons are well-known examples, c. Digiti 

 grades keep the heel raised above the ground, walking on 

 the toes. The majority have long tails. Such are the 

 Weasels, Otters, Civets, Hyenas, Foxes, Jackals, Wolves, 

 Dogs, Cats, Panthers, Leopards, Tigers, and Lions. The 



FIG. 350. Southern Sea-lion (Otaria jubata). Antarctic Ocean. 



last five differ from all others in having retractile claws, 

 and the radius rotating freely on the ulna. The Cats 

 have thirty teeth ; the Dogs, forty -two, or twelve more 

 molars. In the former, the tongue is prickly ; in the 

 latter, smooth. 



12. Prosimii or Lemurs. These singular mammals, 

 sometimes included in the next order, have affinities with 

 Rodents, Insectivora, and Primates. They are covered 

 with soft fur, have usually a long tail, pointed ears, fox- 

 like muzzle, and curved nostrils. They walk on all fours, 

 and the thumb and great toe are generally opposabie to 

 the digits. The second toe has a long, pointed claw in- 



