78 



LARAMIE FLORA OF THE DENVER BASIN. 



ganled as fquixalcnl tu 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 

 his conclusions as to the Tertiary age of the 

 beds in question.'* 



The latest and most authoritative statement 

 is that published by C. F. Bowen " 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 mi.xing of 

 horizons in the earlier collections of vertebrate 

 remains, as I pointed out '" 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 Ri\'er 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 " in his w-ork farther west in Montana, 

 though he ilid not firul it possible to recognize 

 all tlie units present at the mouth of Judith 

 River, 



It therefore seems settled that the Juditli 

 River formation is not to be regarded as of 

 Laramie age. 



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



"' Bowen, C. F., The straligrapliy of the Montana group, with special 

 reference to the position and ajie of the .ludith River formation in north- 

 central Monlana; V . S. Ceol. j^nrvey Prof. Paper 9t), pp. li.Vl.^, 191.^. 



** Kiiowlton, F. II., Remarks on the fossil turtles accredited to the 

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

 1911. 



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

 U. S. Gcol. Suri'ey Prof. Paper ilO, pp. 61-68, 1914. 



BEAR 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 w^ere at first, in 1860, and for 

 many 3'ears 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 w4ien the Laramie was promulgated the 

 Bear River bods were immediately mapped by 

 King and otliers — in this convenient catchall. 

 They came later to be known as the "Bear 

 River Laramie." 



In 1891 T. W. Stanton '- 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,«= published in 1S92 and 1S95, 

 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 liave a very definite sig- 

 nification and delimitation, but during tlie 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. 9S, 1892. 



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

 the Bear Kiver Laramie: Am. Jour. Sci., 3d ser., vol. 43, pp. 91-97, 1!«2; 

 The Bear River formalion and its characteristic fauna; U. S. Geol. Sur- 

 vey Bull. 128, 1895. 



