446 CARNEGIE INSTITUTION OF WASHINGTON. 



Range began to lift its head. It is important to know the age of this 

 deposit. If it is Pleistocene, as Bretz and Williams are disposed to 

 regard it, the Cascades are geologically yoimg. Fossil vertebrates in 

 the deposits in the Cascades appear to be rare. Dr. Bretz has sent 

 the writer a photograph of a tooth found in the Satsop of Gilliam 

 County, Oregon, which appears to belong to the common mastodon 

 of the Pleistocene. From ash beds near The Dalles, which seem to 

 belong to the Satsop, Dr. Ira A. Williams has sent a tooth which the 

 writer identifies as tliat of Elephas primigenius. These proboscidians 

 appear to fix the beds in the Pleistocene. In case the deposits of the 

 Willamette Valley are synchronous with the Satsop, the latter cer- 

 tainly belongs to the Pleistocene; for in that valley have been found 

 elephants, mastodons, and two or three species of horses, among 

 which is Equus laurentius, a not uncommon species in the Aftonian 

 of the lower Missouri Valley. The fossils so found appear to indicate 

 the first interglacial as the age of the Satsop. They do not, however, 

 preclude the reference of the formation to the first glacial stage; and 

 there are some reasons for connecting these deposits with those of 

 the Idaho formation. In his report for 1920 (Year Book No. 19, p. 

 403) the writer by error referred this supposed oldest Pleistocene to 

 the first interglacial instead of the first glacial. 



The strip of country lying between the Front Range in Colorado 

 and the Plains, only a few miles wide, has furnished an interesting 

 series of vertebrates, all of which appear to belong to the early Pleis- 

 tocene, probably the Aftonian. Horses and camels and Elephas 

 imperator have been found at several places along this strip, especially 

 in the so-called loess at Denver (Hay, Proc. U. S. Nat. Mus., vol. 32, 

 pp. 599-603). 



New Mexico furnishes few Pleistocene vertebrate fossils, but the 

 geology is interesting and the fossils, which include horses and camels, 

 are (at least mostly) those of the early Pleistocene. Near Zuni, 

 McKinley County, a musk-ox, Gidleya zuniensis, has been found 

 associated with a camel, thus carrying the musk-ox group back to 

 the early Pleistocene. 



In the paper just quoted (pp. 617-638) the writer has described a 

 collection of mammals made at Anita, Arizona, about 40 miles north 

 of Williams, on the railroad going to the Grand Canyon, About 15 

 species are described. Among the species found are two of horses 

 (Equus), two of camels (Procamelus) , and a large carnivore believed 

 to be a hyena. These species are regarded as belonging to the first 

 glacial stage of the Pleistocene, the Nebraskan. 



