84 
ruminating animals. 
considers them as one of tlie most natural and best 
determined groups among the Mammalia. The ex- 
ternal characters may be placed here, to indicate the 
order : “ Incisive teeth only in the lower jaw, where 
they are generally eight in number. In the upper 
jaw, instead of teeth, there is a callous pad. Be- 
tween the incisive teeth and the grinders there is 
generally an empty space ; but in a few genera, as 
the Camels and Musks, this is partly supplied by 
one or two canine teeth sometimes assuming the 
form of tusks. The grinders are almost always six 
on each side of each jaw, and have their crown oi 
surface marked with two double ciosses, of which 
the convexity is turned inwards in the upper teeth, 
and outwards in the lower. The four feet are ter- 
minated by two toes, defended by two hoofs, which 
are applied to each other with a flat surface, so as 
to resemble a single hoof which has been cleft. Be- 
hind these hoofs there arc sometimes two small or 
nidimentary hoofs, which are the only appearances of 
lateral toes : the two metacarpal and metatarsal bones 
are united in one, which receives the name of ‘ Can- 
non hone’* The head is most frequently furnished 
with horns, sometimes common to both sexes, some- 
times confined to the male only, deciduous, or with 
a bony core. The hair is sometimes crisp, thick, 
and slightly curled, or long, and bearing the title of 
• In some species there are traces of lateral metatar- 
sal and metacarpal bones. 
