Douglass : Vertebrate Fossils from Fort Union Beds. 13 



that of the Puerco and Torrejon of New Mexico. From Mr. Silber- 

 ling's accounts and the data with the collections, it would appear 

 that this micro-fauna is of the same age as the larger mammals 

 in the collection {^Pantolambda, Euprotogonia, etc.). From a chart 

 and section which Mr. Silberling has kindly sent me, I judge that 

 his collections are all from the same band — perhaps not more 

 than 40 to 60 feet wide — from which the present writer obtained 

 Anisonchus, Euprotogonia, Mioclceiius, and Fa^itolambda in 1901. 

 The principal source of these small mammals is a stratum of greenish 

 sandstone, which Mr. Silberling found near Bear Butte. He quarried 

 out some of this rock, broke it up, and found a considerable number 

 of remains of mammals which have not been found elsewhere. Judg- 

 ing by the sketch and diagram which he sent to me, this layer is about 

 75 feet lower than the sandstones which form " the rim " of Bear Butte. 

 This would be approximately in the same general horizon from which 

 I obtained the specimens above mentioned. 



The following list shows the fossils described in this paper, which, 

 judging by the matrix, came from this quarry. Undoubtedly some of 

 the other specimens carne from the same place. Others came from the 

 gray shales and from the layers or lenses containing Unios, which are 

 75 feet or more below the " rim rock." 



Chi) ox No. 1 10 1. 



Chirox No. 1012. 



Ptilodtis montantis No. 1673. 



Ptilodtis montamis No. 1682. 



PtiloJtis montanns No. 1 684. 



Cimolcstes ? No. 1013. 



Picrodus silberlingi , No. 1 670. 



Coriphagus montanus No. 1 699. 



Alegopterna minuta No. 1675. 



Mixodectes ? No. 1672. 



Tricentes ? No. 1677. 



Trice ntesf No . 1676. 



MiocLrmis , No. 1 680. 



Pnntolainbda Silberling, Coll . 



Order ALLOTHERIA Marsh. 



Family BOLODONTIDyE Osborn. 



Chirox Cope, 



(Proc. Am. Philos. Soc, XXI, 1884, p. 321.) 

 This genus is represented by three teeth : one tritubercular premolar 



