VERTEBRATA. 351 



broad, shallow hoofs, and also with a thick, tegumentary 

 pad. The knee is below and free from the body, as in 

 Monkeys and Men. Clavicles are wanting. The body of 

 the Elephant is nearly naked ; but the Mammoth, an ex- 

 tinct species, had a covering of long woolly hair. Ele- 

 phants live in large herds, and subsist on foliage and grass. 

 .There are but two living species: the Asiatic, with long 

 head, concave forehead, small ears, and short tusks ; and 

 the African, with round head, convex forehead, lai-ge ears, 

 and long tusks.'" 



10. Ungulata, or Hoofed Quadrupeds. — This large or- 

 der, comprehending many animals njost useful to Man, is 

 distinguished by four well-developed limbs, each furnished 

 with not more than four , complete toes, and each toe in- 

 cased in a hoof. The leg, therefore, has no prehensile 

 power; it is only for support and locomotion. Clavicles 

 are wanting ; and the radius and ulna are so united as to 

 prevent rotation. There are always two sets of teeth, i. e., 

 milk-teeth are succeeded by a permanent set. The grind- 

 ers have broad crowns. As a rule, all are herbivorous. 

 The brain is always convoluted, but the cerebellum is 

 largely uncovered. 



Ungulates are divided into the odd and even toed. a. 

 The Odd-toed, as the three-toed Khinoceros and Tapir,"' 

 and the one-toed Horse.'" The first is distinguished by 

 its very thick skin, the absence of canines, and one or two 

 horns on the nose. The Tapir has the four kinds of teeth, 

 and a short proboscis. The dental formula of the Horse 

 is — 



• 3-3 p 1-1 piyi 3-3 ^^ 3^-3 AQ 



'^3 — 3' 1 — 1-^ 3 — 3 3—3 



The canines are often wanting in the mare. The Horse 

 walks on the third finger and toe. The metacarpals and 

 metatarsals are greatly elongated, so that the wrist and 

 heel are raised to the middle of the leg. h. The Even-toed 



