310 Mammals of Eastern Asia 
Pigs, Peccaries, and the Hippopotamus, which have well-devel- 
oped upper incisors and are not ruminants, are separated as the 
Suborder Suina. Next, the Camels and Llamas, neither of which 
are known in eastern Asia, which retain upper incisors and have 
the molars composed of sharp, moon-shaped sections, form a 
second suborder, the Tylopoda. Third, the little Mouse Deer 
of the Family Tragulidse have so many unusual or peculiar 
characters that they are placed in a suborder by themselves, the 
Tragulina. Fourth, the three remaining families of artiodactyls, 
comprising the Cattle, Antelopes and Sheep, the Giraffes and the 
Deer, all of them ruminants, go into a single huge suborder, the 
Pecora (from Pecus, Latin for "cattle"). In this last belongs 
also the American Pronghorn, last survivor of a long line of 
fossil ancestors that with it form the Family Antilocapridae. 
The Suborder Pecora have the stomach more complex than 
have other ruminants. The swallowed food is received in the 
first and largest of four divisions of the stomach, where it under- 
goes a kind of predigestion. It is regurgitated into the mouth 
where it is rechewed, a process known as "chewing the cud." 
In the less specialized Tylopods and Chevrotains the stomach 
has only three divisions. 
The Pecora of eastern Asia are restricted to the Bovidse or 
Cattle family, and the Cervidse or Deer family. An excellent 
way to distinguish between these is to remember that the first 
have horns which are never shed but grow as the coverings of 
bony horn cores projecting from the frontal bone, and that the 
second have antlers that are shed every year, developed at the 
end of bony pedicels. 
THE PIGS (FAMILY SUID^e) 
The familiar characters of the Pigs include the long snout 
ending in the flat, expanded mobile disk in the middle of which 
the nostrils are placed ; the small eyes and long ears ; the strong, 
