1094 The Artiodactyla. 
that genus, and probably with the fifth crescent of the superior 
molars. Agriochcerus may have been derived from the same. 
Pithecistes. 
Cyclopidius. 
Leptauchenia. 
Merychyus. 
Merycocheerus. 
Eucrotaphus. (Tragulide) 
Oreodon, Dorcatherium. 
Coloreodon. 
Agriocherus. 
| Dichodon. = S 
er 
Ree | 
S 
y 
The genealogical positions of these genera are as follows : 
White | John Ticho- |; Lou 
Oreodontine. No, of River Day leptus Fork | 
Species | Epoch Epoch Epoch Epoch 
Oreodon Leid 3 
Eucrotap wee 3 
Merycochcerus Leidy 8 adic | plese} a + ea 
Merychyus Leidy 6 nn e 
eptauchenia Leidy 3 PREDAN 
Cyclopidius Cope 2 rani 
thecistes Cope 3 TREIA 
Pith 
Er n ae 
The numbers of individuals of Oreodontidæ which must have 
existed during the Miocene period in North America is so great a5 
to astonish the paleontologist. During the White River epoch 
droves of Oreodon culbertsoni inhabited the swamps, and the small 
O. minor was abundant. Several forms, perhaps species, coe 
with these two. During the John Day epoch Oregon and adjacent 
regions were overrun by the Eucrotaphus pacificus, and the large 
and formidable Meryeochoerus superbus (Plate XX VI). Ata still 
later date, in the Ticholeptus epoch, the species of Cyclopidius were 
scarcely Jess abundant. All of these forms were the prey of num- 
erous Carnivora, mostly false sabre-tooth or half sabre-tooth cats, 
