24 Annals of the Carnegie Museum. 



of this horizon, none were found at the top by the parties from the 

 Carnegie Museum, but it is quite probable that true Cyclopidius may 

 occur in the upper levels. Other changes of the fauna occur which 

 help to identify the horizon. 



List of the Fauna. 



? Diceratherium. 1 These genera are found in the 



Mesoreodon. lower levels of the beds and may 



Leptauchenia. \ with equal propriety in part be re- 



Cameloid fragments (Genus?). I garded as belonging to the fauna 



j of the Gering horizon. 



Canid fragments (Genus?). 1 

 Euhapsis platyceps Peterson. 



Promerycocharus carrikeri, n. sp. These genera and species are 



Phenacocoelus typus, gen. et sp. j- f rom the upper Monroe Creek 



nov. horizon. 

 Protomeryx cederensis Mat hew. 



Nothocyon lemur Cope. J 



Description of New Material. 

 Diceratherium sp. indet. 



A few fragments of jaws and teeth were found in the lower level of 

 the Monroe Creek beds which evidently belong to the genus Dicera- 

 therium. The incisor is large and apparently occupied the usual pro- 

 cumbent position which is characteristic of the family. The specimen 

 is probably that of an earlier type of the genus. 



Mesoreodon melagodon sp. nov. 



In the collection of the Carnegie Museum are five or six individuals 

 upon which this species is founded. The material was found in the 

 middle and lower Monroe Creek beds near Squaw Butte, Sioux County, 

 Nebraska. All the specimens are crushed and the true contour of the 

 skulls is consequently lost. 



The front of the skull and lower jaws (No. 1325) of a young indi- 

 vidual, but with all the permanent teeth in position (see Fig. 2) are 

 selected as the type. A second specimen of a fully adult animal (No. 

 1323) is chosen as the paratype, and consists of the back part of the 

 skull, the lower jaws very nearly complete (see Fig. 3), fragments of 

 lumbar vertebne, fore and hind limbs, and feet. 



