98 Annals of the Carnegie Museum. 



had a large lengthened snout or proboscis. How long it was of 

 course is not known but it was probably quite long. The position of 

 the condyles and the extremely heavy mandible indicates that the 

 head was carried with the facial axis in approximately a vertical position 

 or approaching a right angle to the vertebrae of the neck. 



If we may judge by what appears to be its nearest known relatives, 

 and by what few fragments of bone are preserved, this animal was 

 short limbed, like most of the later Merycoidodonts ; but we must 

 await the discovery of more complete skeletons. 



V. Age of the Flint Creek and Madison Valley Beds. 



These beds both belong to the Loup Fork Epoch as it is usually 

 understood. Either they are not quite contemporaneous or else they 

 represent a somewhat different ecological condition, at least there is a 

 different assemblage of fossils. This will be thoroughly discussed 

 later after a revision of the fauna has been made. My lagan li dec., but 

 perhaps of different genera, occur in both formations, Pronamotherium 

 appears in the Flint Creek Beds and a related form Pronomotherhi7n 

 altiramus in the Madison Valley Beds. Palceomeryx ? appears in both 

 beds but of smaller size in the latter. Procamelus of large size occurs 

 in both. 



On the other hand Mylagaulus is found in the Flint Creek and Deep 

 River beds. Ticholeptus occurs in the latter, and perhaps in the former, 

 as the specimen, Merychyus smithi is much more like Ticholeptus. 

 Palceomeryx ? borealis occurs in the Deep River beds, and what 

 appears to be the same species, in the Flint Creek beds. 



It appears most probable, from the evidence, that the Flint Creek 

 beds are in some ways intermediate between the Deep River and 

 Madison Valley formations, yet some things in the first seem more 

 modernized or specialized than in the last, yet we cannot judge by 

 this, for there have been very highly specialized mammals all along 

 the line, and some characters that were supposed to be modern are quite 

 ancient. A careful study of the Horses, Camels, and other fossils of 

 these beds may furnish a better basis for correlation. 



Matthew 26 thinks that the Pawnee Creek Loup Fork holds a position 

 distinctly lower than that of the Niobrara, Santa Fe, and the Repub- 

 lican River Basin. "It seems most nearly equivalent to the upper 

 beds of Smith Creek, Montana (Deep River substage)." 



26 " Fossil Mammals of Colorado," pp. 373-4. 



