648 REPORT OF NATIONAL MUSEUM, 1904. 



cussion brought out man} 7 interesting facts and opinions relative to 

 the proportional value of the various kinds of fossil remains as horizon 

 markers, the subject may be dwelt upon in some detail. 



It is well to anticipate, however, in order to more readily understand 

 what is to follow, that Hayden made a fundamental error in thus 

 assuming an identity of age for all the lignite strata. Had he realized 

 the fact, afterwards abundantly proven, that essentially similar condi- 

 tions existed at various periods in localities not widely remote from 

 one another, and which were productive of very similar results, the 

 so-called " Laramie question," as it is known to-day, would never have 

 arisen. The apparently conflicting character of the fossil remains of 

 plants and animals was, nevertheless, extremely confusing, and some 

 discussion and verbal warfare during the gradual accumulation of the 

 necessary data for the final settlement of the problem was bound to 

 arise. . It will be well to note, further, that the localities from whence 

 was derived the major portion of the evidence brought to bear 

 were: Fort Union, Nebraska; the Judith River, on the upper Missouri, 

 Montana; Coalville, Utah; and Bear River and Bitter Creek, in 

 Wyoming. Incidentally, other localities in Colorado and New Mexico 

 came in for discussion. 



During the season of 1872 Lesquereux, Meek, and Cope were assigned 

 by Hayden to work in areas which seemed to afford the most promising 

 opportunities for deciding the question as to the precise position of 

 the beds in the geological scale. Their reports as rendered in the 

 annual reports for 1872-73 were widely divergent and did little more 

 than to emphasize the existing confusion. 



Lesquereux worked, of course, wholly from a paleobotanical stand- 

 point. He explored the plant-bearing Cretaceous strata of the Dakota 

 group and the valley of the Saline River, as well as the Smoky Hill 

 Fork of the Kansas River and the Lignite formations of the Rocky 

 Mountains from Trinidad to Cheyenne and along the Union Pacific 

 Railroad to Evanston. He made extensive collections and studied the 

 materials in great detail, comparing the forms found with those from 

 sundry of the known geological horizons in Europe. The summary 

 of his conclusions, as given in his own words, was to the effect 



That the great Lignitic group must be considered as a whole and well-characterized 

 formation, limited at its base by the fucoidal sandstone, at its top by the conglom- 

 erate beds; that independent from the Cretaceous under it and from the Miocene 

 above it our Lignitic formations represent the American Eocene. 



Meek regarded the Coalville and Bear River beds as Cretaceous, 

 but argued for the Bitter Creek beds that the entire absence among 

 the invertebrate fossils yet found of Baculites, Scaphites, Ancyloceras, 

 Ptychoceras, Ammonites, Gyrodes, Anchura, hwceramus^ and all of the 



