206 



University of California Publications. 



| Geology 



Moropus( ?), sp. 

 Blastomeryx mollis, n. sp. 

 Dromomeryx, sp. a, near borealis (Cope). 

 Meryeodus, near f meatus (Leidy). 

 Mastodon (Tetrabelodon ?, sp.). 

 Camel, near Proca?nelus. 



Nearly all of the species from this locality are found also at 

 other places and presumably at other horizons. The only form 

 not known elsewhere is Palacolagus, represented by a single speci- 

 men. The relative abundance of material at this place would 

 make probable the discovery here of some of the rarer forms. At 

 other localities considered as higher in the section than no. 1065 

 the species are largely the same as at this horizon. "With these 

 are a few rare forms, as Merychyus and T1iinohyus( ?), known 

 by only one or two specimens, and representing groups typical 

 of horizons much older than the lowest Virgin Valley beds are 

 presumed to be, so that there is reason to believe that they were 

 present during the deposition of the lowest mammal-bearing beds, 

 but are sufficiently rare to have escaped observation in collecting 

 this far. The only other important forms not known in the lowest 

 horizon are Aplodontia and Probassariscus, each known by a 

 single specimen. The specimen of Aplodontia is doubtfully higher 

 in the section than the beds at locality 1065. Probassariscus was 

 presumably a little higher. 



From the above statement it appears that the fauna of the 

 various localities in Virgin Valley is practically a unit, and may 

 be considered collectively in any attempt at correlation. 



Faunal Relationships. — The closest relationship of the Virgin 

 Valley fauna seems to be with that of the Mascall Beds of Oregon 

 and of the Pawnee Creek Beds of Colorado. The Snake Creek 

 Beds of Nebraska contain a larger percentage of the Virgin 

 Valley species than either the Mascall or Pawnee Creek, but 

 there seems, nevertheless, good reason for considering the rela- 

 tionship with the other faunas as closer. 



The ungulate fauna of Virgin Valley fauna resembles that of 

 the Mascall in the presence of Hypohippus, Parahippus, Mery- 

 chippus, and Dromomeryx ; and in the persistence of at least one 

 oreodont (Merychyus?) . The brachyodont horse Hypohippus 



