The hoofed Mammals, or Ungulates. 
ORDER UNGULATA. 
Tlie Order Uxgulata comprises alxxut 300 species, of which 
half occur in the Ethiopian Region, where the great Family 
Bovidae predominates. Ungulates are found all over the World 
except in the Australian Region. The Sew World is particularly 
poor in them: only about 12 per cent of all the known species occur 
in that half of the globe. 
Limbs. [Hate I] 
One of the general characteristics of most Mammals is 
that the fore and hind Limbs have five digits, which are sup- 
plied with claws or thin nails. One important group, however, 
known as the Ungulates or Hoofed Mammals, differs from 
this general mammalian plan in the digits of the fore and hind- 
limbs being encased in solid hoofs. In a few cases broad fiat 
nails take the place of the c-laws in other mammalian Orders, 
With the exception of the Elephant and some extinct species, 
the Ungulates never have more than four digits, while in some 
species the number is reduced to three, two, or even one as in 
the horse. These Hoofed Mammals are placed in tJie Order 
U JvGCLATA, A further peculiarity of the Ungulates is that the 
fore limbs are restricted to movement in one plane; lateral or 
rotatory movement of tin* fore limb, such as may be seen in 
other mammals, e.g. monkeys, cats, squirrels, is impossible. 
Several well-known mammals fall into this Order: ele- 
phants, rhinoceros, cattle, horses, giraffes, camels, pigs and 
deer. Although differing so much in size and general appear- 
ance they all share this common character of the limbs, and 
therein differ from all other mammals. 
The reduction of the usual mammalian five-toed limb to 
a more specialized type is of sufficient importance to merit 
a more detailed explanation. Ungulates are essentially terre- 
strial animals, for whom the development of strong walking 
or running powers has become essential ; hut the development 
of prehensile li mbs has not proved necessary or taken plaqe 
(except in the elephant whose prehensile trunk is useful 
enough to rank as a fifth ** limb.”) 
Two lines of reduction can be traced : one from a three- 
toed to a one-toed state, the other from a four-toed to a two- 
toed state. Animals belonging to the former category are 
styled PermoductyJa or “ Odd-toed Ungulate's/* while those 
in the latter are named .lrftockcfy/a or “ Even-toed Ungu- 
lates” 
