1884. ] The Creodonta. 481 
TII. Inferior molars sectorial. 
Last superior molars transverse; others with two median cusps; formula $ 3, 
Pterodon. 
Last superior molar subround ; others with one median cusp; formula $ $, 
Thereutherium. 
Fic, 25.—Oxyena lupina Cope, jaws, one-half natural size, from the Wasatch 
beds of New Mexico. Fig. a, maxillary bone with teeth, from below; 4, last supe- 
nor molar, from behind. Original from the Report U. S. G. G. Survey W. of tooth 
mer., G. M. Wheeler, 
Of the above genera Oxyzena and Protopsalis only are Ameri- 
eres Thereutherium Filhol, includes a species, P. thy/acoides, 
with a skull of the size of that of a skunk, which has been ob- 
tamed from the Phosphorites of France. There are two species 
of Pterodon, both robust flesh-eaters. The P. dasyuroides of De 
Blainville is one of the longest known of the Creodonta. The 
i onyetis gigantea Blv., is found in the plastic clays near Paris. 
dentition approaches that of Amblyctonus. 
do € Oxyænas have the characteristic peculiarities of the Creo- 
á nta and of the carnivorous marsupials in their general propor- 
Pes The head was relatively larger, and the limbs were smaller 
iain in true Carnivora. The feet were plantigrade, and had five 
m 7 and posteriorly. The hind foot was either divided 
> that the external two toes opposed the internal three, or were 
vergent and connected by.a median web. If not divided, the 
In mig directed outwards from the line of the calcaneum. 
opossu case the hallux may have been opposable, as in the 
sto m, but in a much less degree. The tail was long and 
ut (Fig. 26). 
in New = this genus were abundant during the Wasatch epoch 
tinent, an and Wyoming, and probably over the entire con- 
"i eens have not yet been reported from higher Eocene 
Sven occurring in the Wind River. A small species is 
