98 
CEEODONTA. 
eniarginate. None of them present the triangular.section characteristic of 
many recent Carnivora. Their proportions are not different from those seen 
in the TJrsns arctos. 
But few vertebrm have been preserved: those of the tail indicate that 
that member Avas of full proportions. 
This genus resembles Fterodon^ as described and figured by Gervais, in 
the dentition of the maxillary bone; but the teeth of the loAver jaw are totally 
distinct in character, approaching more nearly those of the Palrvonyctis of 
De Blainville. According to Gervais,* the inferior molars of Pterodon are 
like those of Hyc&nodon, Avithout interior tubercle, and the inner lobes of the 
superior molars are not so large as in Oxyczna. The latter differs from Pa- 
JcBonyctis in the character of the antepenultimate lower molar, Avhich, in 
OxycBna, is characterized by the presence of a median blade, but, in PalcRO- 
nyctiSj by a heel supporting (in the typical species) two tubercles. 
The Oxyaenas Avere the most abundant of the Eocene Carnivora.^ esti¬ 
mating them by the relative frequency of occurrence of their remains. 
There Avere at least three species, which ranged from the size of a Terrier- 
dog (0. morsitom) to that of a Jaguar {0. forcipata). They are of robust 
structure, and resemble Synoplotherium in the anterior production of their 
canine teeth, Avhich are so closely approximated as to exclude the. incisors 
altogether. Specimens obtained include the dentition of both jaAvs and 
bones of the skeleton. The phalanges have the same flattened form seen 
in the flat-claAved genera discovered in Wyoming, but I haA^e not been so 
fortunate as to obtain those of the ungues. 
Oxy^na morsitans, Cope. 
Plate xxxLv, figs, l-lll. 
Eeport Vert. Foss. New Mexico, U. S.'Geog. Survs. W. of lOOth M., 1874, p. 12; Id. 
Ann. Eeport U. S. Geog. Survs. W. of lOOtb M., 1874, i). 124. 
This, the smallest species of the genus, is represented by parts of the 
skeletons of three individuals, while others in the collection probably belong 
to it. The original description was based on a series of inferior molars, 
found in association by myself, but not attached to the jaAV. A second 
specimen includes a portion of the jaw Avith the last three molars, and a 
* Pal6ontologie Irangaise. 
