736 MANUAL OF ZOOLOGY. 



and their allies, in which the whole, or nearly the whole, of 

 the foot is applied to the ground, so that the animal walks 

 upon the soles of the feet (fig. 424, A). 



Section III. Digitigrada. This section comprises the Lions, 

 Tigers, Cats, Dogs, &c., in which the heel of the foot is raised 

 entirely off the ground, and the animal walks upon the tips of 

 the toes (fig. 424, C). 



SECTION I. PINNIGRADA or PINNIPEDIA. This section of 

 the Carnivora comprises the amphibious Seals and Walruses, 

 which differ from the typical Carnivores merely in points con- 

 nected with their semi-aquatic mode of life. The body in 

 these forms is elongated and somewhat fish-like in shape, 

 covered with a short dense fur or harsh hairs, and terminated 

 behind by a short conical tail. All the four limbs are present, 

 but are very short, and the five toes of each foot are united 

 together by the skin, so that the feet form powerful swimming- 

 paddles. The hind-feet are of large size, and are placed far 

 back, their axis nearly coinciding with that of the body (figs. 

 424, 425). From this circumstance, and from the fact that the 



Fig. 425. The Greenland Seal (Phoca Grcenlandica). 



integument often extends between the hind-legs and the sides 

 of the short tail, the hinder end of the body forms an admir- 

 able swimming apparatus, similar in its action to the horizontal 

 tail-fin of the Cetacea and Sirenia. The tips of the toes are 

 furnished with claws, but the powers of terrestrial locomotion 

 are very limited. On land, in fact, the typical Seals can only 

 drag themselves along laboriously, chiefly by the contractions 

 of the abdominal muscles. On the other hand, the Eared 

 Seals (Otariadce) can use their hind-limbs freely upon the land. 

 The ears are of small size, and are mostly only indicated by 



