86 CONTRIBUTIONS TO PAL^ONTOLOGY 



skioldi Heer and Trapa? microphylla Lesquereux, were found to be valid; both of 

 these species are, however, long-ranging forms of little value for correlation. 



Although the obviously mixed collection of Lance Creek specimens did not add 

 any appreciable weiglit to his argument, Knowlton was by this time thoroughly 

 convinced by accumulatcd evidence from elsewhere that the flora of the "Ceratops 

 beds" and their supposed equivalents elsewhere could not be distinguished from the 

 Fort Union flora. The stratigraphic misconceptions which led him to this conclu- 

 sion have been discussed elsewhere.^ 



Thc "Ceratops beds" of the Lance Creek area were discussed again in the same 

 3'ear by Stanton,- who reiterated his opinion regarding the Cretaceous age of the 

 beds as determined by their stratigraphic relations, their vertebrates, and their 

 invertebrates. In the foUowing year, Stanton first appUed the name Lance forma- 

 tion to the "Ceratops beds," as foUows: 



'*Tlie namc Lance formation has recently been adopted by the United States Geological 

 Surs'ey for the 'Ceratops beds' of eastern Wyoming and adjacent areas. It is an abbreviated 

 form of the term 'Lance Creek beds' which J. B. Hatcher applied to these deposits . . . with the 

 statement that the name is taken 'from the principal stream in the region where they are best 

 represented in Converse County, Wyoming.'" ' 



In this report Stanton was primarily concerned with the stratigraphic relations of 

 the Lance formation. In the Lance Creek area, and elsewhere, he observed that 

 there was no evidence of an unconformity between the Lance and the underlying 

 Fox Hills sandstone, such as had been postulated by some geologists. He pointed 

 out also that the Fox Hills sandstone of the Lance Creek area was somewhat thicker 

 than had previously been determined, and estimated the thickness of thc Lance 

 formation at 2100 to 2200 feet. 



Within the next few years the controversy concerning the Cretaceous-Tertiary 

 boundary in the western interior reached its cUmax. The Lance Creek area, how- 

 ever, was no longer the focus of attention. In 1911 Knowlton ^ described a new 

 species from his Lancc Creek coUections but did not discuss furtlier the qucstion of 

 the age of the flora. In 1912 Winchester ^ described a section from the Pierre shale 

 to the Fort Union in the Lance Creek area, in which the Lance formation was esti- 

 mated to be 2539 feet thick. CoUections of invertebrates, vertebrates, and plants 

 were obtained from a number of locaUties. Problems of correlation were not dis- 

 cussed. The area was only brieUy mcntioned in connection with the symj)osium 

 on the "Close of the Cretaceous and Opening of Eocene Time in North America" 

 of 1913-1914.'' 



In the summer of 1914 LuU vi.sited the Lance Creek area, and subsequently he 

 I)ul)Ushed an exccUent summary of the known vertebratc remains, both mammaUan 

 and dinosaurian, which had by this time becn coUected from the Lance formation of 



■ Dorf. K.. Bull. Geol. Soc. Amer., vol. 51, 213-230. 1940. 



•Stanton, T. W., Proc. Washington .\tad. .Sci., vol. II. 241-244, 1909. 



» Stanton, T. W., Amer. Jour. Sci., 4th ser., vol. 30, 172, 184, 1910. 



• Knowlton, F. H., Bull. Torrey Bot. Chib. vol. 38, .389, 1911. 

 > Winchestcr, D. E.. U. S. Geol. Surv. B\ill. 471. 477, 1912. 



• Osborn, H. I'., Knowlton, F. H., et al., BuU. Geol. Soc. .-Vmer., vol. 25, 321-102, 1914. 



