Cope.} 570 (Jan, 18, 
The skulls of this species came from the John Day bed of the John Day 
river, Oregon, and were found by Mr. J. L. Wortman. The species was 
established on an immature individual. The adults show that it belongs 
to this genus. 
COLOREODON Cope. 
Proceedings American Philosophical Society, 1879, p. 875. 
Superior premolars three, the fourth with two external Vs, no facial va- 
cuities. 
The mandibles of the species of this genus are unknown, so that the 
character of the inferior dentition is unknown. The otic bulla are also 
destroyed in all the specimens, so that their character is unknown. 
In its reduced dental formula this genus represents one stage of that 
specialization which Owen has shown, has overtaken all the modern types 
of Mammalia. In this series this process seems to have stopped at this 
point, and not to have gone further, as the entire line has come to an end. 
The first superior premolar probably exists in a rudimental condition for 
a short time, and is early shed. The same state of things has been found 
to exist as an abnormality on one side in the Agriocharus guyotianus, and 
may be found again, but not so as to invalidate the characters of the genus 
Ooloreodon. 
Two well-marked species of this genus have been described, which dif- 
fer as follows: 
Smaller ; palatonareal border opposite posterior cusps of second 
true molar; sagittal crest anterior, commencing opposite 
OPtic FOAMING... 6 ccereeseerererneereceeseresees sete wan Ong Crows 
Larger; palatonareal border opposite posterior cusps of third 
true molar; sagittal crest posterior, commencing opposite 
preglenold border. .cccsceceosessraeteesrsscvesees Os macrocephalus. 
Coloreodon ferox Cope. Fig, 1, p. 505. 
Proceedings American Philosophical Society, 1879, p. 375. 
The size of Oreodon culbertsont. Known from one skull from the North 
Fork of the John Day river, Oregon. OC. H. Sternberg. 
Coloreodon macrocephalus Cope. 
Proceedings American Philosophical Society, 1879, p. 876. 
Size of the Hucrotaphus major. The typical skull is from the North 
Fork of the John Day river. A second skull, lacking all the parts posterior 
to the anterior origin of the sagittal crest, is undistinguishable from the 
first. It was tound at the ‘‘Cove’’ of the John Day river, Oregon. Both 
were obtained by Mr. J. L. Wortman. 
