378 Scientific Intelligence. 



The John Day and Mascall formations ai'e almost entirely ash 

 and volcanic tuff in various forms. The mammal remains are 

 from the John Day, Mascall, Rattlesnake, and Terrace deposits. 

 The John Day consists for the most part of evenly stratified 

 beds containing a characteristic dry land fauna ; the higher 

 strata, however, are crossbedded and contain fresh-water types. 



The lower Mascall is composed of fresh-water sediment con- 

 taining fresh-water fishes, molluscs, and fossil plants, while the 

 upper portion consists of evenly stratified ash beds like those of 

 the John Day. 



The carnivora of the Tertiary faunas of the John Day region 

 are known through numerous types, but the actual number of 

 specimens is not large and may be counted among the rarities. 

 It is probable that the fauna is still only imperfectly represented 

 in the collections. Carnivora are known as yet only from the 

 John Day and Mascall formations of this series, the distribution 

 of species being as f ollows : 



Middle John Day 11 species, 23 specimens. 

 Upper John Day 6(?) species, 12 specimens. 

 Mascall 2 species, 2 specimens. 

 There is also a considerable number of species of which the 

 geological range or occurrence is unknown. 



Canidce. — There is a remarkable variety of canid types com- 

 pared with those of other formations in America, nearly all from 

 the John Day beds ; as but two of the eighteen species are from 

 the Mascall. Most of the types exhibit primitive characters 

 though much variation in structure is shown, and in some cases 

 differentation has led to the development of considerably spec- 

 ialized forms. 



Compared with the canids of other Tertiary formations in 

 America, the John Day clogs represent a stage of evolution 

 which does not correspond to that of any other formation. Of 

 the nine generic types but one, Cynodictis is considered identical 

 tvith a White River genus ; the type is, however, much more 

 advanced than the White River species. The genera have all 

 advanced along lines of specialization laid down in the White 

 River epoch. 



The Mascall is separated from the John Day by at least one 

 period of erosion and by the epoch of the accumulation of the 

 Columbia Lava. The relationships of the Mascall Canidse and 

 the stratigraphic relations taken together indicate that the epoch 

 of the Mascall beds is not far from that of the Deep River. 

 The position of the John Day below these beds puts it into a 

 division much earlier than the Loup Fork. 



Felidce-. — Though fairly well-known from skulls and teeth, 

 the John Day cats have, as a whole, presented some of the most 

 puzzling features of this fauna. The most common and best 

 known forms included in the genera Archculurus and N'imraous 

 have been generally considered as representing the most primi- 

 tive division of the machaerodont group of the Felidse. In the 



