220 DOUGLASS — CRETACEOUS AND LOWER TERTIARY. [Aprils 



thousands of feet of sandstone which, if marine, must be near-shore 

 deposits? It is true that any day we may hear of their being found 

 in some of these strata, and we may also hear of their being found 

 in Eocene strata, if they have not been found there already. 



As shown by this paper, the presence of Claosauridce, and proba- 

 bly of Ceratopsldce, is far from showing that the beds in which they 

 are found are as late as Laramie — I mean as the Laramie as it is 

 understood. It is true that the Fort Pierre, and in some places the 

 Fox Hills with it, represents an incursion of the sea, and that con- 

 ditions of life were not greatly different during the time of the 

 deposition of the Belly River beds from what they were in the 

 Laramie. 



At present the fossil plants, together with orographic movements 

 and their results when they occur, are the only things we can use to 

 distinguish these doubtful formations as the Laramie, Livingston, 

 Denver, etc. The plants, on account of mixtures of the flora of 

 different horizons in collecting, have not been available for use until 

 the material has been carefully separated. As Mr. Knowlton has 

 been doing this work, his forthcoming monograph on the Flora of 

 the Laramie and Allied Formations will be looked for with interest. 



There is not much doubt that the Livingston in Montana repre- 

 sents the upper portion of what has been called the Laramie in the 

 plains region farther to the east. Both have Laramie strata below ; 

 both are overlaid by Fort Union beds. In Colorado it seems that 

 the Arapahoe, and probably the Denver, or the greater part of it, 

 sustains the same relation to Laramie. Mr. Knowlton says : ^' From 

 these considerations it appears beyond question that the flora of 

 the Livingston formation finds its nearest relationship with the Den- 

 ver beds of Colorado," ' If the Livingston and Denver are of the 

 same age, as has for some time been suspected, then the Denver 

 must be older than the Fort Union, and therefore older than the 

 Torrejon. With its apparently Cretaceous Vertebrate fauna, we are 

 not warranted at present in placing the Denver much higher than 

 the Livingston. It may be in part contemporaneous with the Fort 

 Union. 



The Puerco should be nearly of the same age, as it lies between 

 Laramie and Fort Union (Torrejon) strata. 



Below is given a table which is intended to show the probable 



1 Bull. 105, U. S. Geo I. Survey, p. 63. 



