152 Annals of the Carnegie Museum. 



has made concerning the habitat of extinct mammals are worthy of the 

 most careful thought and study. 



In this same region to-day there are animals that live high among 

 the rocks of the mountain peaks. These we would expect to be ex- 

 tremely rare in lacustrine or fluviatile deposits. Others, like some 

 species of deer, live principally in the wooded mountains and drink 

 from mountain streams. These under present conditions would sel- 

 dom be preserved, yet, when lakes and marshes were more extensive, 

 and when the valleys were not cultivated, the chances would be greater. 



It is interesting to notice the difference in habits of domestic 

 horses and cattle, when left to themselves. Domestication has not 

 entirely changed their natures. In this mountainous region horses 

 will come down to the streams from the dry hills to drink once in 

 one, two, or three days according to the weather. They come in 

 bands, usually in the afternoons of hot summer days, drink their fill, 

 and go far back to the hills, perhaps miles from their watering places. 

 Cattle remain nearer to water as they are not so " well built for speed," 

 come down to streams and ponds to drink, and linger in or near the 

 water during the heat of the day. They often die near these water- 

 ing places. In swamps they get mired, and not having the strength 

 to extricate themselves, leave their bones in a favorable place for pres- 

 ervation. It is easy to see which of these animals, cattle or horses, 

 under present conditions would stand the better chance of being pre- 

 served in aqueous deposits ; though any animal going to a watering 

 place during its last sickness is very apt to leave its bones near by. 



Last summer the party in charge of the writer found a place in the 

 Deep River beds, where skulls and portions of skeletons were abun- 

 dant ; but with the exception of turtles and some mammalian frag- 

 ments, they all belonged to the Oreodontidcu. In one locality on the 

 North Boulder only turtles, camels, and horses were found. The lat- 

 ter probably represents a little later phase of the Loup Fork, yet no 

 one would claim that in either case the fossils were a just representa- 

 tion of the fauna of the times. It is possible that these Oreodonts 

 found in marshes, where other mammals seldom came, their most 

 natural feeding ground. 



The Deep River Beds. 

 For a description of these beds in their typical locality near White 

 Sulphur Springs I would refer to Scott's valuable paper, The Mam- 



