GEOLOGICAL SURVEY OF THE TERRITORIES. 107 



merits at the bottom. As the gregarious ruminants came down to the 

 little streams or by the shores of the lake to quench their thirst, they 

 would be pounced upon by the flesh-loving Hyaenodon, Drepanodon, 01 

 Dinictis. It was probably near this place also that these animals would 

 meet in fierce conflicts, the evidences of which remain to the present 

 time in the cavities which the skulls reveal ; one of these, of a huge 

 cat, shows on either side the holes through the bony covering which had 

 partially healed before the animal perished, and the cavities seem to 

 correspond in form and position with the teeth of the largest Hysenodon. 



The remains of those animals which, from their very nature, could not 

 have existed in great numbers, are not abundant in the fossil state, 

 while those of the ruminants occur in the greatest abundance and are 

 widely diffused in the sediments not only geographically, but vertically. 

 The chances for the preservation of the remains of a species seem to 

 depend upon the number of individuals that existed. The remains of 

 ruminants already obtained comprise at least nine-tenths of the entire 

 collection, while of one species, portions of at least seven hundred indi- 

 viduals have been discovered. We might take examples from the ani- 

 mals that exist in this region at the present time that Avould illustrate 

 the point. The wolves watch the deer, antelope, and other feebler ani- 

 mals as they go down to the little streams for water, and all over the 

 wide bottoms their skeletons are distributed in a more or less perfect 

 condition. Whenever a bison becomes too feeble by disease or age to 

 offer a successful resistance, the wolves soon dispatch him, and his bones 

 are left bleaching on the ground. In most cases these animals when 

 pursued betake themselves to the water, where they are not unfrequently 

 drowned, or dispatched on a sand-bar or island. Annually, thousands 

 of buffaloes, in attempting to cross the Missouri Eiver and some of its 

 lajjge tributaries on the ice as it is breaking up in the spring, are 

 drowned. For many days their bodies are seen floating down the river 

 by Fort Union or Fort Clark, and lodging on some of the islands or 

 sand-bars fill the air with the stench of their decay. In the spring of 

 1857 thousands of their bodies floated down the Kansas Eiver past Fort 

 Eiley and were carried into the Missouri Eiver. These animals are often 

 mired in the marshes or the muddy shores of lakes or streams in great 

 numbers. We know what vast numbers of the mastodon have been 

 preserved in the Big Bone Licks of Kentucky, <and of the Irish elk in 

 the bogs of Ireland. We might instance hundreds of examples to show 

 how easily these animals, roaming and feeding along the numerous 

 streams flowing into some great lake, could be transported in part or 

 entire into the lake, and sinking to the bottom would be enveloped in 

 the muddy sediments. 



There is another interesting feature in regard to these remarkable 

 fossils, and that is the beauty and perfection of their preservation ; the 

 bones are so clean and white and the teeth so perfect that, when ex- 

 posed upon the surface, they present the appearance of having bleached 

 only for a season. They could not have been transported from a great 

 distance, neither could the waters have been swift and turbulent, for 

 the bones seldom show any signs of having been water worn, and the 

 nice sharp points and angles are as perfect as in life. I have dwelt thus 

 long on the details of this great lake basin, not only on account of the 

 universal interest that invests it, and the wonderful treasures of the 

 past which it has revealed to the world, but because its history is ap- 

 plicable in the main to the numbers of the other fresh- water lake basins 

 of the geological past which are distributed throughout the Eocky Moun- 

 tain region. 



