UNGULATA VERA 275 
which the vast majority of modern Ungulates belong the second or 
distal row has been shifted altogether towards the inner side of the 
limb (see Fig. 99), so that the magnum is brought considerably 
into relation with the scaphoid, and is entirely removed from the 
cuneiform, as in the great majority of existing mammals. 
It will be on the whole more convenient to commence our 
survey of the members of this suborder with the more specialised 
group of the Ungulata Vera, in which the Artiodactyla will be 
taken first. 
UNGULATA VERA. 
In the typical Ungulata the feet are never plantigrade, and the 
functional toes do not exceed four—the inner digit being suppressed, 
at all events in all forms which have existed since the Upper 
Eocene period.2. The os magnum of the carpus articulates freely 
with the scaphoid. The allantois is largely developed, and the 
placenta, so far as is known, is non-deciduate ; the chorionic villi 
being either evenly diffused or collected in groups or cotyledons (in 
Pecora). The testes descend into a scrotum. There is never an os 
penis. The uterus is bicornuate. The mamme are usually few 
and inguinal, or may be numerous and abdominal (as in Suina), but 
are never solely pectoral. The cerebral hemispheres in existing 
Ungulates are well convoluted. 
The group is now, and has been throughout almost the whole 
of the Tertiary period, composed of two perfectly distinct sections, 
differing from each other, not only in the obvious characters of the 
structure of the limbs, but in so many other parts of their organisa- 
tion that they must be considered as of the rank at least of 
suborders. The characters of these divisions, first indicated by 
Cuvier, were thoroughly established by Owen, by whom the names 
whereby they are now generally known were proposed. 
Suborder ARTIODACTYLA. 
This is a well-defined group, traceable from the Eocene period, 
though then apparently by no means so numerous as the Perisso- 
dactyles. Some of its types, as that represented in the existing 
Swine, have retained to the present time much of the primitive 
character of the group; but others have been gradually becoming 
more specialised and perfected in structure, and its latest modifica- 
tion, the Cavicorn Ruminants or Luride (Antelopes, Sheep, and 
Oxen), are now the dominating members of the great Ungulate 
order, widespread in geographical range, rich in generic and specific 
variation, and numerous in individuals—forming in all these 
1 Also known as Diplarthra. 
? The pollex is present in the manus of the extinct Cotylops. 
