Geology. 379 



White River beds, held to be older than the John Day, there 

 appeared to be among the felines no forms so primitive as these. 

 As the other elements of the John Day fauna are nearly all more 

 advanced than the corresponding forms of the White River, the 

 evidence regarding the age of the beds which is furnished by 

 these cats seemed to contradict that of the remainder of the 

 fauna. The persistence of the primitive running type of feline 

 seems due to the fact that the country was in the main open and 

 ill suited to the development of the larger, slower animals upon 

 which the more specialized saber-toothed cats preyed. 



The nine species of Felidse described are entirely confined to 

 the John Day, none being known from the Mascall. In the 

 Loup Fork, however, the species of true Felis and of Machcero- 

 dus represent a more advanced stage of development and a closer 

 approximation to the recent fauna than is found in either the 

 John Day or the White River. 



Conclusions. — Taken together the Canidse and Felidae of the 

 John Day represent a stage of evolution somewhat more advanced 

 than that reached in the White River, and less advanced than 

 that of the Loup Fork. Compared with the known faunas of 

 Europe, they appear to be not older than the Middle Oligocene 

 of Fontainbleu, and not as young as the Middle Miocene of 

 Sansan. e. s. l. 



3. A Lower 3fiocene Fauna from South Dakota ; by W. D. 

 Matthew. Bull. Amer. Mus. Nat. Hist., vol. xxiii, art. ix, pp. 

 169-219. — In this bulletin Dr. Matthew announces the discovery 

 of a fossil fauna which links the latest of the White River with 

 the earliest of the so-called Loup Fork fauna? of the western 

 plains. This gap had been filled in part bj r the John Day of 

 Oregon, but this is much more nearly allied to the White River 

 than to the Loup Fork. 



Matthew and Gidley have given the name Rosebud Beds to 

 the Lower Miocene formation of South Dakota lying between the 

 White River and Loup Fork. These beds are divided by a 

 white, flinty, calcareous layer lying about half way up, into an 

 upper and a lower series, each with its characteristic animal 

 forms. 



In the Lower Rosebud Matthew has identified five new species 

 of Carnivora, nine species of Rodentia, of which six are new, three 

 species of Perissodactyla, and six of Artiodactyla, one of which he 

 describes as new. The Upper Rosebud fauna is almost entirely 

 distinct, few species passing through. It contains four new species 

 of Carnivora, one of which is the type of a new genus, a new genus 

 and species of Insectivora, four new species of Rodentia and one 

 form representing an undetermined genus, five species of Artio- 

 dactyla of which three are new, and one new genus and at least 

 three species of Perissodactyla. The Rosebud fauna is derived 

 from the John Day, there being but one immigrant, the antiloca- 

 prid Blastomeryx. The species are in advance of those of the 

 John Day, though the great majority can be referred to John 

 Day genera. 



