294 UNGULATA 
the earliest known, .fuoplotherium, was fully described by Cuvier 
from remains found in the Paris gypsum-beds (Upper Eocene). 
Its forty-four teeth formed a series unbroken by « gap or diastema, 
and were of uniform height (as in Man alone of existing mam- 
mals). Its tail was long, with large chevron bones underneath, 
not usually found in Ungulates, and there were either three or 
two toes on each foot. It was in many respects a much- 
specialised form, apparently not on the line of descent of any of 
the existing groups. 
Dacrytherium is an allied genus whose dentition leads on to that 
of the smaller Viphodon. The latter genus is characterised by the 
compressed and elongated form of the crowns of the first three 
premolars, which thus approximate to those of the Chevrotains. 
There were only two functional digits to the feet. The so-called 
HHyopotamus pieteti, of the Swiss Eocene, is a species of Dacrytherium. 
Cenothertide.—The typical representatives of this family are 
small animals not larger than the Chevrotains, with the full comple- 
ment of teeth, generally no marked gap in the series, and the 
crowns of the upper molars carrying two columns on the anterior 
and three on the posterior half of the crown—precisely the reverse 
of the arrangement obtaining in the //nthracotheriidw. The known 
forms are from the Upper Eocene and Lower Miocene of Europe. 
In Cenotherium the molars are selenodont, while they are bunodont 
in Dichobunus. LHomacodun, of the Bridger Eocene of the United 
States, is closely allied to the the latter. The first lower premolar 
of Dichobunus assumes the form and function of a canine. Spunio- 
thertum (Metriotherium) is a much larger form, in which the molars 
are not unlike those of /uthrucotherium, if the arrangement of the 
cusps were reversed; it occurs in the Eocene Phosphorites of 
France. It is suggested that the Z'ylopulu may have originated 
from this group. 
Tapirulus is a small Eocene Artiodactyle with the columns of 
the upper molars, which are somewhat like those of Myopotanus, 
tending to form transverse ridges ; its family position is uncertain. 
Dichodontide,—The European genera included in this family all 
have quadritubercular selenodont molars, and show signs of approxi- 
mating more or less closely to existing types.  Michulon, from the 
Upper Eocene and Lower Miocene, has the full complement of teeth, 
which show no diastema, and have low crowns. The fourth upper 
premolar has four columns, like the true molars, and the corre- 
sponding lower tooth three complete lobes; these features being 
unknown in any other Sclenodonts. In Lophiomerys, of the same 
heds, the somewhat higher crowns of the molars approximate to 
those of the Cervidir, but the hinder lobes of the upper ones are 
imperfectly developed ; the genus may he allied to the Traqulide, 
In the small Gelocus, of the Lower Miocene, the molars are not 
