460 THE AGE OF MAMMALS 



the types E. padficus and E. ocddentalis. The most numerous forms next 

 to the horses were the cameloids, animals identical neither with the existing 

 camel nor llama, referred by Cope to the genera Eschatius and Camelops, and 

 distinguished from recent llamas (Auchenia) by the greater reduction of the 

 premolar teeth, a feature which is especially marked in the genus Eschatius. 

 This animal is also found in the valley of Mexico. Among the burrowing 

 forms were the pocket gophers {Thomomys bulbivorus, T. clusius). Geomys 

 also occurs. Hares {Lepus campestris) are very abundant. The peccaries 

 are represented by two species of Platygonus. There are also prong-horn 

 antelopes (Antilocapra) . The only carnivore recorded by Cope is the 

 prairie wolf, or coyote (C. latrans), but Matthew has added the gray wolf 

 (C. cf. ocddentalis) ^ an animal of the size of the timber wolf. The record 

 of a bear (Ursus) by Cope is not confirmed. The arrowheads and flints 

 found on the surface of these deposits are probably of recent age. 



Silver Lake avifauna and climate. — It is a very fortunate circumstance 

 that the contemporaneous bird life of Silver Lake is fully known through 

 the rich deposits investigated by Shufeldt^ (1892). The bird life was very 

 abundant and not very dissimilar from what we might observe at any of 

 the alkaline lakes of the West, resorted to at the present day by the wild 

 fowl during their migrations. Great flocks of swans (Cygnus paloregonus) , 

 geese {Anser condorii), and ducks were there; a cormorant (Phalacrocorax) 

 was among the rarities; among the species of grebe is one (Podiceps ocd- 

 dentalis) still frequenting this region. There were also coots (Fulica minor) 

 and herons (Ardea paloccidentalis) . Other forms of birds include two 

 species of grouse, crows, and eagles. The strangest figure upon the scene 

 among the birds was a true flamingo (Phoenicopterus copei). The north- 

 ernmost distribution of the flamingoes at present is southern Florida and 

 the Bahama Islands (lat. 27° N.). Shufeldt concludes that the climate 

 might well be compared with that of Florida or the lower part of Louisiana, 

 that the vegetation was fully as luxuriant as it now is in those parts, and 

 that the palms were abundantly represented. This conclusion as to a 

 Floridian climate and the existence of palms is, however, very questionaljle. 

 Brown ^ observes that the South American flamingoes {Phoenicopterus chilen- 

 sis) migrate as far south as the lakes in central eastern Tierra del Fuego, 

 lat. 53° S., where they are said to breed, and certainly spend a part of 

 the season. This region corresponds in temperature to the climate of 

 central Alberta, Canada, 400 miles north of Silver Lake. Thus it appears 

 that the presence of Phoenicopterus copei at Silver Lake has little weight in 

 the determination of climate. It is more probable that the northern lakes 

 of that period contained molluscs on which the flamingoes fed. 



1 Matthew, W. D., List of the Pleistocene Fauna from Hay Springs. Bull. Amer. Mus. 

 Nat. Hist., Vol. XVI, Sept. 25, 1902, pp. 317-322. 



^ Shufeldt, R. W., A Study of the Fossil Avifauna of the Equus beds of the Oregon Desert. 

 Jour. Acad. Nat. Sci. Phila., Vol. IX, 1892, pp. 389-425. 



* Mr. Barnum Brown in a note to the author. 



