Hatcher : Tiik Jirassic I)in(isair Dkposits. 



3;}9 



About one quarter of a mile southwest of the "Nipple" near the 

 top of this same thirty feet of chocolate-colored shale and just beneath 

 a thick layer of white sandstone, which is generally placed as the base 

 of the Dakota, is an old abandoned quarry worked by Messrs. Lucas 

 and Russell for the late Professor Cope, and from which they recovered 

 for him the beautiful skeleton of Camarasaurus now in the American 

 Museum of Natural History in New York. This is a distinctly higher 

 horizon than the one at the "Nipple." A view of the abandoned 

 workings at this quarry may be seen in Fig. 5 where the light colored 

 Dakota sandstones appear resting on the dark, chocolate-colored shales 

 which bear the dinosaurian remains. Owing to the poor light in the 

 deep trench leading to the quarry the shaly structure of the latter is 

 not shown in the photograph. 



Fig. 5. Eastern entrance to Cope (luarry. Lijjjlit colored Dako'a sandstone at top 

 underlaid by chocolate-colored shales with remains of Camarasaurus. 



A number of other bone -bearing horizons have been detected, but 

 as yet they have not been sufficiently prospected to determine their 

 richness. Heretofore the entire series and the succeeding Dakota 

 formation has been considered as of fresh water origin. But on his 

 last visit to this locality the writer discovered casts of shells of Ino- 



