214 DOUGLASS — CKETACEOUS AND LOWER TERTIARY. [Aprils^ 



belonging to Ciaosaurus. The only fossil plant we were able to 

 recognize in the field was a species of Salisbu7'ia. 



Though this is probably still below the Laramie — at least there 

 are thousands of feet of what is apparently Laramie above it — yet 

 this is the highest level in which we found Dinosaur xtmdXns in this 

 region. This is interesting, as in other regions the Ciaosaurs, with 

 one exception, have come from beds which have been supposed to 

 be above the Fox Hills. 



It is not certain just where the Fox Hills ends and the Laramie 

 begins. It is possible that these bones, or at least some of them, 

 are in the lowest Laramie ; but as the two formations represent 

 differences in conditions of depositions rather than difference in 

 age, as distinguished by change or progression of the fauna or flora, 

 it is not so essential, except as bearing on the more interesting ques- 

 tion of the extinction of a very remarkable class of animals and 

 the occupation of their territory by a class that had for millions of 

 years held a subordinate position. 



Above the Pierre, in the Fish Creek region, are alternations of 

 dark shales and gray sandstones. In places the sandstone is warped, 

 twisted or made up of imperfectly concentric layers. Above these 

 are brownish laminated and greenish or brownish unlaminated 

 sandstones and sandy clays. Provisionally, I place the base of the 

 Laramie above these latter beds. They contain fossil leaves and 

 bone fragments. 



Laramie, 



The lowest beds, which are here taken to be Laramie, are a series 

 of alternating various-colored shales and gray unlaminated sand- 

 stones. There are several hundreds of feet of these and no fossils 

 were found in them. There are in some layers brownish concre- 

 tions, some of which are large and composed of sandstone. These 

 beds form a depression, but not so low as that of the Pierre shales. 



Over these lies about an equal thickness of similar sandstones and 

 gray shales. The former are harder and form a bench or ridge. 

 .There are several thin seams of coaly matter and the shales hold 

 impressions of ferns and other delicate plants different from what 

 we observed elsewhere. 



Near or at the top of this series there are at least two layers 

 containing non-marine fossils. In one of the fossils are principally 

 Gasteropods and in the other bivalves — probably Unio. It 



