"As stated before, Wyoming has no equal as a fossil field, and while expedition after 

 expedition has taken away material by the car load, the fields are large and hundreds of 

 square miles have never been visited by geologists. 



"On account of the numerous mountain ranges the rocks are tilted about our great 

 field, and erosion has cut deep valleys and canyons leading from them, which makes it 



DORSAL VERTEBRA OF BRONTOSAURUS. 

 Height, 44 inches. University of Wyoming. Prom Converse County, Wyo. 



possible to examine every foot of a formation in detail. In many places the later forma- 

 tions have been deposited in interior seas, and these have been eroded down to their base, 

 so that the entire section is exposed. 



19 



