1889.] The Artiodactyla. 119 
which the fusion of the trapezoidesand magnum in the tarsus, 
has not yet taken place. The metapodials then rest on a 
single carpal or tarsal bone each, instead of on two, as in 
modern didactyle genera, representing the inadaptive type of 
Kowalevsky. DicJiodon aispidaUis is about the size of a fal- 
low-deer. Smaller species have been found in Germany. 
The genus is probably represented in North America by 
Stibarus Cope, of the White River bed. I have associated 
provisionally with the Dichodontidae two North American 
genera, Agriochoerus Leidy (Plate III.), and Coloreodon Cope 
(fig- 5)- These genera differ from Dichodon in having the 
first premolars in both jaws molariform or nearly so, and in 
having the other ones much less compressed, except the 
fourth inferior, which is caniniform, as in Oreodon. There are 
four premolars and little or no diastema in Agriochoerus, 
and three premolars and a long diastema in Coloredon. The 
former possesses six species, which are equally divided between 
the White River and John Day beds.and the latter, two spe- 
cies from the John Day Miocene. Their feet are unknown. 
The remaining families of the Cameloidea are the Poebro- 
theriidae, Protolabididae, Camelidae and Eschatiidae. I have 
already described their characters in the pages of the Nat- 
uralist.' I will only add to that account the interesting 
discovery made by Profs. Scott and Osborn, of a third genus of 
Poebrotheriidae which they call Leptotragulus. It differs 
from Poebrotherium and Gomphotherium, in the separate 
condition of the ulna and radius.' It is from the highest 
Eocene beds of Utah (Brown's Park, or Uinta system), and 
thus stands in ancestral relation to Poebrotherium. 
The Cameloid phylum presents a noteworthy peculiarity. 
The Poebrotheriidse have acute trihedral ungual phalanges 
like those of most other Artiodactyla. In the Camelidae, in- 
cluding the extinct genus Procamclus, the ungual phalanges 
are short and obtuse, and apparently undergoing atrophy. 
This form is associated with the presence of a cushion of con- 
nective tissue on the inferior side of the phalanges, which 
My knowledge of this genus is entirely derived from the unpublished mss 
