W. Cross — Denver Tertiary Formation. 277 



1888,* Mr. Cannon gave a review of the circumstances attend- 

 ing the finding of all Dinosaur bones known to that time in the 

 Denver beds, and drew the conclusion that they must belong 

 to the horizon in which they were found. 



The majority of the bones thus far secured were apparently 

 isolated, no adjacent parts of a skeleton being found together, 

 though different parts of the animal are represented. The 

 finds thus indicate skeletons which have been dismembered and 

 the various parts separated, though not very widely. Bones 

 found imbeded in Denver sandstones are never worn, the 

 articulations of ribs and leg bones are sometimes perfect, and 

 delicate surface sculpturing uninjured. The bone matter 

 is soft and could not have withstood transportation under 

 ordinary circumstances. In the strata containing the bones 

 are no pebbles of earlier sedimentary formations, and any 

 agency which could have transported the bones uninjured 

 would have left traces of the rocks from which the bones were 

 derived. The present softness of the bones is not due to 

 decomposition ; on the contrary, the original bone substance 

 seems to be well preserved, for analysis shows eighty per cent 

 of lime, phosphoric acid, and fluorine, in a typical specimen of 

 bone material. It is also observed that fragments washed out 

 of the Denver strata and now found lying in small gullies have 

 been very much worn, even when carried but a few yards. 



In the article cited Mr. Cannon also mentioned the finding 

 of various fragments apparently belonging to one animal, in 

 strata of South Table Mountain. He further stated that a 

 number of bones belonging to an herbivorous Dinosaur had been 

 obtained on the eastern slope of Green Mountain within a 

 small area. 



On January 7, 1889, Mr. Cannon gave a preliminary account 

 before the Colorado Scientific Society of a quantity of large 

 bones recently exposed by a cloud burst on Green Mountain at 

 the spot where the before -mentioned bones were found. All 

 these bones seem to belong to a large Dinosaur. 



These later finds confirm the conclusions reached by study of 

 the isolated bones. Until the new material has been studied 

 by Prof. Marsh the full import of the discovery cannot be 

 known, but it makes it clear that Dinosaurs lived in the Den- 

 ver epoch. 



Discussion of Evidence. 



The strata here assigned to the Denver Formation have 

 hitherto been considered as typical Laramie, but solely on 

 account of their plant remains. No other evidence has been 



*The Mining Industry, Denver, Nov. 9, 1888. 



