78 



LARAMIE FLORA OF THE DENVER BASIN. 



garded as equivalent to the lower part of the 

 Lance formation. 



, Peale's view was essentially sustained by 

 Charles H. Sternberg, in a short paper pub- 

 lished in Science for July 25, 1914, based on 

 the recollection of 30 years before, when he 

 had assisted Cope in collecting the vertebrate 

 forms that later came into prominence in con- 

 nection with this problem. In 1914, however, 

 Sternberg again visited the region about the 

 mouth of Judith River and completely reversed 

 bis conclusions as to the Tertiary age of the 

 beds in question. 78 



The latest and most authoritative statement 

 is that published by C. F. Bowen 79 in 1915, 

 Which presented the result of- several seasons' 

 work in this and adjacent areas. In general 

 Bowen agreed with the statements of Stanton 

 and Hatcher, namely, that the Judith River is 

 the equivalent of the Belly River of Canada 

 and is of Montana age. He recognized, how- 

 ever, that there was possibly some mixing of 

 horizons in the earlier collections of vertebrate 

 remains; as I pointed out 80 in regard to the 

 turtles, and said that to this may be due the 

 confusion that has resulted. Bowen wrote as 

 follows : 



The extensive faulting that ; has disturbed the strata 

 along Missouri River renders it possible, though it is not ex- 

 tremely probable, that blocks of the Lance formation may 

 be faulted down among the beds of Judith River age and 

 that some of the vertebrates collected by Hayden and 

 others "from the badlands of the Judith'' may have been 

 obtained from the Lance formation instead of the Judith 

 River formation, as they supposed. 



The results obtained by Bowen, as set forth 

 above, were essentially duplicated by Stebin- 

 ger 81 in his work farther west in Montana, 

 though he did not find it possible to recognize 

 all the units present at the mouth of Judith 

 River. 



It therefore se,ems settled that the Judith 

 ' River formation is not to be regarded as of 

 Laramie age. . . , . , * 



" Science, new ser., vol.''42, p. 131, 1915; 



'» Bowen, C. F., The stratigraphy ,qf, the Montana group, with special 

 reference to the position and age of t he Judith River formation in north- 

 central Montana: TJ. S. Geol. Survey Prof. Paper 90,-pp. 95-153, 1915. 



™ Knowlton, F. H., Remarks on the fossil turtles accredited to the 

 Judith River formation: Washington Acad. Sci. Prqc, vol. 13, pp. 51-65, 

 1911. ' * 



si Stebinger, Eugene, The Montana group of northwestern Montana: 

 U. S. Gebl. Survey Prof. Paper 90, pp. .61-68; 1914, : 



BEAE RIVER FORMATION. 



The Bear River formation, as it is now called, 

 has given rise to almost as much discussion and 

 difference of opinion as the Judith River forma- 

 tion, just mentioned. It comprises a series of 

 purely fresh-water strata of considerable areal 

 extent, mainly in the valley of Bear River in 

 southeastern Wyoming and adjacent Idaho. 

 With the exception of a few unidentifiable frag- 

 ments of dicotyledonous leaves and a single 

 species of Chara — a fresh-water alga — its only 

 paleontologic contents known are numerous 

 invertebrates of fresh-water types and a few 

 brackish-water forms. On account of the sup- 

 posed affinities of these invertebrates the beds 

 containing them were at first, in 1860, and for 

 many years thereafter referred with little hesi- 

 tation to the Tertiary. Then, as certain differ- 

 ences came to be detected, it was hinted by 

 Meek and others that the age might possibly be 

 latest Upper Cretaceous instead of Tertiary, 

 and when the Laramie was promulgated the 

 Bear River beds were immediately mapped by 

 King and others — in this convenient catchall. 

 They came later to be known as the "Bear 

 River Laramie." 



In 1891 T. W. Stanton 82 was able to show 

 that this formation, previously considered to 

 be of Laramie or later age, is in reality interme- 

 diate between the Jurassic and the Colorado 

 Cretaceous. Of its thirty or more species of 

 invertebrates none have been found in the true 

 Laramie. Thus another supposed Laramie 

 area has been eliminated. The complete his- 

 torical summary of opinion regarding the Bear 

 River formation may be found in two papers 

 by C. A. White, 83 published in 1892 and 1895, 

 to which\the reader desiring further details is 

 referred. 



PRESENT USAGE OF THE TERM LARAMIE. 



The term Laramie, as originally established 

 by King, seemed to have a very definite sig- 

 nification and delimitation, but during the 40 

 years after it was first defined it had come, 



" The stratigraphic position of the Bear River formation: Am. Jour. 

 Sci., 3d ser., vol. 43, p. 98/1892. 



" On the Bear River formation, a series of strata hitherto known as 

 the Bear v River Laramie: Am. Jour. Sci., 3d ser., vol. 43, pp. 91-97, 1892; 

 The Bear River formation and its characteristic fauna: TJ. S. Geol. Sur- 

 vey Bull. 128, 1895. 



