734 JAMES H. GARDNER 



indicate. The evidence as to the age of these beds is conflicting 

 when viewed from different paleontological standpoints, and has led 

 to an interesting discussion by Stanton^^ and Knowlton.^^ But so 

 far no fossils of the lower formation of the Nacimiento group, or 

 Puerco, have been found in Montana. It is quite possible that they 

 may be discovered later either in lower beds of the Fort Union or in 

 the underlying Lance formation. 



There is one locality on the south side of the San Juan Basin, 

 namely at Ojo Alamo (see Plate II), where the writer obtained dino- 

 saurs from beds unconformably above the "Laramie" and below 

 the Wasatch. Mr. C. W. Gilmore of the U.S. National Museum 

 reports that they appear to represent a typical fauna of the " Ceratops 

 beds." The beds at Ojo Alamo have been searched in vain for fossil 

 mammals and have furnished several new species of fossil turtles, 

 but the fact remains that so far they have not been correlated with 

 any other formation of that basin. They are very similar in appear- 

 ance to the beds of the Nacimiento group, are only a short distance 

 west of the Puerco region, and occupy the interval between the "Lar- 

 amie" and Wasatch. Their definite relation to the Nacimiento 

 group must be left for future elucidation. 



There are two foreign countries where faunas closely related to 

 those of the Nacimiento group have been found, one in Europe, the 

 other in South America. 



The Thanetien, or Cernaysien, of France, corresponds broadly, 

 with the Puerco and Torrejon.s^-^s.es ^g pointed out by Osborn,^^ 

 the fauna of the "Conglomerat de Cernay" near Rheims shows a 

 homotaxis with that of the Torrejon by similar stages of evolution 

 in the representatives of three families, namely, (i) Plagiaulacidae, 

 (2) Arctocyonidae, and (3) Mesonychidae-Triisodontidae. Other 

 identifications are very uncertain.^^ Professor Charles Deperet, 

 of the University of Lyons, correlates the beds of Cernay with those 

 near La Fere, Rilly, Chalons-sur-Vesle, in France, and the Erguelines 

 in Belgium. 



In South America, the basal Eocene or Notostylops beds of 

 Patagonia contain fossil mammals similar to those of the Puerco 

 formation,^s thus probably indicating a contemporary or previous 

 land connection between the two Americas. 



