200 Bulletin American Museum of Natural History. [VoL XIX, 



Palseolagus temnodon Douglas. \_ More primitive than Middle Oli- 



" brachyodon, sp. nov. S gocene species. 



Perissodactyla. 



Mesohipptts westoni Cope. More primitive than Middle Oli- 



gocene species. 

 Hyracodon sp. 

 ? Csenopus sp. 

 Titanotherium sp. 



Artiodactyla. 



Stibarus montanus sp. nov. 

 Bathygenys alpha Douglas. 

 Limnenetes sp. div. 

 Leptomeryx mammifer Cope. 

 " ? esulcatus Cope. 



Leptntragiihis profecttis sp. nov. Advanced species of an Eocene 



genus. 



Lizards and Tortoises, sp. div. 



Two species are reported by Mr. Douglas of which we 

 obtained no further evidence: Sciitrus jejfersoni Douglas, 

 ? Agriochcerus maximus Douglas. 



The Oreodon Beds are buff clays, somewhat harder than 

 the Titanotherium Beds, finer, not sandy, more calcareous, 

 and not unlike the Oreodon Beds of Dakota and Colorado. 

 They were very barren so far as we could discover, and the 

 only determinable fossils found at Pipestone Springs were: 

 Palceolagus haydeni, Eiimys elegaiis, Mesohippus bairdii, 

 ? Poehr other ium. 



These are all characteristic species of the Oreodon Beds in 

 South Dakota, Colorado, etc. 



The fauna from the Titanotherium Beds is a quite remark- 

 able one. Not a single species is identical with those of the 

 Oreodon horizon; all are either new, or have been described 

 by Douglas from the same locality, or by Cope from the same 

 horizon at Swift Current Creek. The majority of the species, 

 however, belong to genera of the Oreodon Beds, and these, 

 though fairly distinct, are not widely divergent from their 

 successors. We find that the Pipestone Beds are much 

 nearer to the Oreodon horizon than to the upper Uinta or 

 Diplacodon Beds. Fourteen genera are in common with the 



