1847.| OWEN ON EXTINCT ANTHRACOTHERIOID QUADRUPEDS. 137 
PEDES are raised to the rank of Orders, forming the VII", VITI™ 
and IX" of the series ; the Order X., Ruminans, forming an equi- 
valent group. The succession of the genera is as follows :—lephas, 
Loxodon, Mastodon, Rhinoceros, Tapirus, Hyrax, Paleotherium, 
Lophiodon, Sus, Babirussa, Phacocherus, Dicotyles, Hippopotamus, 
Anthracotheri ium, Anoplotherium, Xiphodon, Dichobune, Adapis, 
Equus, which is followed by Camelus and the other Ruminants. 
The German and Scandinavian naturalists seem as little as the 
French to have appreciated the true value of the indications of the 
affinities of the Ungulata, afforded by the even and uneven number 
of the digits of the hind-foot: the Hog and the Hippopotamus are 
associated with the Tapir, the Rhinoceros and the Klephant in the 
order Multungula, by Illiger. The Horse-genus forms an order 
Solidungula, equivalent on the one hand to the foregoing, on the 
other to the Bisulca or Ruminants. 
The order Pecora in the mammalian system of Fischer is made 
equivalent to all the rest of the Ungulates, which are collected toge- 
ther into the order BeLuu#, the Artiodactyles and Perissodactyles 
being indiscriminately mingled together. 
Professor Wagner of Gottingen, i in the last edition of his ‘ Lehr- 
buch der Zootomie’ (1845), retains the same primary division of the 
Ungulata with the Cuvierian names Pachydermata, Solidungula, 
Ruminantia. And the learned Nilsson, in his ‘Skandinavisk Fauna,’ 
8vo, 1847, in adopting the two Cuvierian orders PAcHYDERMATA 
and Ruminant1A, divides the former into those with 5 toes (e- 
phas), those with less than 5 and more than 1 (ex. Rhinoceros, 
Hippopotamus, Sus), and those with | only (Zquus). But were 
the proportions of the middle and functional to the two lateral and 
rudimental digits regarded, as they exist in the embryo-Horse, the 
artificial, it might be termed eetatal, nature of the solipedous or 
solidungulate character would be better appreciated. It is probable 
that most of those naturalists who have made the Horse the transition 
from the Pachyderms to the Ruminants have believed its large middle 
metacarpal bone and corresponding metatarsal bone to be, like the 
cannon-bones of Ruminants, a confluence respectively of the proximal 
elements of two distinct digits, and the three successive phalanges 
supported by such metacarpal and metatarsal to be the result of a 
confiuence of as many pairs of phalanges*. Were this so, all the 
views of the affinities of the Horse here advocated would be sub- 
verted ; and from the Perissodactyle it would enter into the essentially 
Artiodactyle group, but would carry with it so many elements con- 
_tradictory of the natural character of that group, as would render 
the proposed arrangement untenable. But the development of the 
feet of the Horse concurs with the structure of the carpus and tarsus 
* The learned Professor of Comparative Anatomy in the University College 
affirms this to be the fact. ‘ We observe that the phalanges, three in number in 
each toe, of the anterior and posterior extremities, are composed each of two 
bones anchylosed together, so that only one toe appears to touch the ground, 
which is covered with a large undivided hoof, from which they are called ‘ Soli- 
dungula.’ ’”’—‘ The anchylosis seen in the cannon-bone of the Ruminantia has 
here proceeded downwards through the whole extent of the feet.”—Dr. Grant’s 
Lectures, ‘ Lancet,’ No. 550. March 1834, p. 907. 
r, 2 
