THE SUID^. 367 



present, they are double, supported, wholly or partly, by 

 the frontal bone and provided with an osseous core, which 

 is almost always an outgrowth from that bone. 



The Artiodactyla are divisible into the Non-Ruminantia and 

 the Buminantia. 



A. The Non-Ruminantia usually have more than one pair 

 of incisors in the upper jaw. The molar teeth have either a 

 matnmillate, a transversely ridged, or a rhinocerotic pattern. 

 In only one genus, Dicotyles, are any of the metatarsal or 

 metatarsal bones ankylosed together. They are devoid of 

 horns, and the stomach has rarely more than two divisions. 



The Non-Ruminantia are divisible into three families : — 

 The SuidcB, the Hippopotamidoe, and the Anoplotheridce. ; but 

 more or fewer of the members of this last group may have 

 ruminated. 



a. The Suidm have the skin of moderate thickness and 

 hairy; the limbs slender, and the third and fourth toes 

 considerably longer than the second and fifth. The teats 

 are abdominal, and there is a scrotum. The dental formula 

 varies considerably, but the molars have a multituberculate 

 or transversely ridged grinding surface. 



3 ■ 3 1 • 1 



In the genus S^is, the dental formula is i. —-: c. ~^ p.m. 



4-4 3-3 



— 7n. — . 



4-4 3-3 



By way of contrast with the Horse, I add some more 

 detailed statements regarding the anatomy of the Pig as a 

 common and very good exam^jle of an Artiodactyle. The 

 Pig has seven cervical vertebrae, nineteen* dorsolumbar, of 

 which fourteen are dorsal, four sacral, and twenty to twenty- 

 three caudal. The atlas has wide oblique alte, as in the 

 Horse. The centra of the other cervical vertebrae are short, 

 with nearly flat articular surfaces, and this flatness is 

 retained in the dorsolumbar region. The cervical and 

 dorsal vertebrae are provided with long spines, that of the 

 first dorsal vertebra being the longest of all. Up to the 

 twelfth dorsal the spines all slope backwards ; beyond it they 

 slope forwards, if at all. 



* Exceptionally, the number may be increased to twenty-two. 



