terminate at a point opposite the post frontal process. The space enclosed 

 in their angle is plane. Space between supraorbital foramina convex. 



The posterior internal tubercle of the fourth premolar is much smaller 

 than the anterior ; the inner basal tubercles of the second and third are 

 subposterior and acute. The length of the diastema is equal to that of the 

 premolar series. The enamel of the molars is wrinkled. The canines are 

 robust. 



Estimated length of skull, M. .200 ; length of superior molar series, 

 .066 ; of diastema, .028 ; diameters of second true molar, — anteroposte- 

 rior, .016, transverse, .017; width of palate at do., .038; interorbital 

 width, .060. 



The strongly developed crests and wide zygomata of this animal, to. 

 gether with the large canine teeth, evidently indicate that it was a formid- 

 able antagonist even for the Garnivora of its time. 



Discovered by Charles H. Sternberg. 



COLOREODON MACROCEPHALTJS, Sp. nOV. 



This Oreodont is considerably larger than the G. ferox, being of the size 

 of the Eucrotaplius major, while the former equals the Oreodon culbertsoni. 

 It also differs from its congener in the relatively longer and narrower 

 frontal region. The sagittal crest is elevated, and divided into two crests 

 opposite the posterior part of the zygomatic fossa. These branches are 

 nearly straight, and diverge at an acute angle, terminating above the 

 postorbital processes. They enclose a deep concavity, which is continuous 

 with the front anteriorly. In G. ferox these crests diverge much more ab- 

 ruptly and widely from a more anterior point, and enclose a much smaller 

 concavity. The supraorbital foramina are close together and are separated 

 by a small protuberance of the middle line. The parietal walls of the tem- 

 poral fossa are rugose. The posterior tubercle of the fourth premolar is 

 well developed, while a single tubercle is present on the preceding premo- 

 lar. 



Length of cranium from inion to above superior canine. M. .230 ; length 

 from superior canine postorbital angle (axial), .124; length from junction 

 of crests to supraorbital foramina, .080 ; interorbital width, .072 ; length of 

 bases of the molars except the last, .050 ; length of three premolars .027. 

 Length of diastema, .030. 



From the North Fork of John Day River ; found by J. L. ^Wortman. 



Printed Dec. 24, 1879. 



