348 THE AGE OF MAMMALS 



rather imperfect specimens, very little doubt remains of the substantial 

 isimilarity in the age of these faunas. We discover here especially the short- 

 footed or teleocerine rhinoceroses of the species T. fossiger. There are also 

 remains of a long-limbed, hornless rhinoceros (Aphelops malacorhinua). 

 Mingled with these are found hipparions (//. ingenuum) . The proboscideans, 

 or mastodons, are . represented by M. (fTrilophodon) floridanus, a species 

 with long, narrow grinding teeth, somewhat akin in their proportions to 

 those of M. angustidens of Europe. There are also remains of a number 

 of camels, including a giant form provisionally referred to Procamelus, l)ut 

 possibly representing the giraffe camel Alticamelus. The deer family is rep- 

 resented by teeth provisionally referred to the Virginia deer Odocoileus, 

 but probably representing an ancestral stage of this animal. The remains 

 of a tapir and of a Megatherium are also attributed to this same zone 

 (op. cit. p. x), but are probably of more recent age. 



The above list of mammals is that recorded from a point ten miles east 

 of Archer, hence these are also known as the 'Archer Beds.' The appear- 

 ance of the bones suggests that the animals were mired and then scattered 

 by predatory Carnivora. Ashes and burnt clay were found beneath some 

 of the bones, but there is no sufficient evidence of human agency in this; 

 the fire may have been due to lightning, a frequent occurrence in Florida at 

 the present time. The longitudinal splitting of the long bones, sometimes 

 observed, may be due to the penetration and growth of roots in the hollows 

 of the bones rather than to the agency of man. 



These details have been dwelt upon at some length because it seems that 

 here we have a source of positive evidence as to the survival of the teleocerine 

 rhinoceros fauna in the southern United States into Pliocene times. 



A much newer or Upper Pliocene fauna is that mistakenly attributed to 

 the Alachua Clays from Ocala, Marion County, Florida, a fauna containing 

 Elephas (E. fcolurnbi), horses (E . fraternus) , llamas (Auchenia), and saber- 

 tooth tigers (Machcerodus). This 'Ocala' fauna corresponds rather with 

 that of the Upper Pliocene or Lower Pleistocene Peace Creek Formation of 

 south central Florida. It may prove that this Florida fauna is 'homo- 

 taxial' rather than 'synchronous' with the Republican River and succes- 

 sive faunas of the Western plains region, which we shall now examine. 



The 'Republican River ' of Kansas. Peraceras Zone 



Here we discover a very rich mammalian fauna resembling that of the* 

 Alachua Clays in the presence of the rhinoceroses Teleoceras fossiger and 

 Aphelops malacorhinus, and also containing the very characteristic rhi- 

 noceros Peraceras, which is believed to be an acerathere, or hornless. 



The typical deposits * are 100 feet in thickness and extend along the 

 Republican River of northwestern Kansas; they are part of the 'Loup 

 Fork' as described by Cope and other authors. 



