8 FLORA OF THE MONTANA FORMATION. 
They were first regarded as Tertiary by Messrs. Hayden ' and Lesquereux. 2 In 
1870 Messrs. Meek and Hayden 3 adopted the view that the Coalville beds are Creta- 
ceous, but that they "occupy a higher horizon in the Cretaceous than even the Fox 
Hills beds of the Upper Missouri Cretaceous series." 
Mr. Meek visited Coalville in 1872, and after making larger collections and study- 
ing the stratigraphy, he decided that the entire Upper Missouri Cretaceous section, 
with perhaps some older beds, is represented here. The detailed section that he 
published 4 shows correctly the essential features of the stratigraphy. The opin- 
ions that he then expressed concerning the correlation of these beds were repeated 
in subsequent publications. 5 
Messrs. King and Emmons 6 assigned the Cretaceous strata at Coalville to the Col- 
orado, Fox Hills, and Laramie formations, and so mapped them in the atlas accom- 
panying their report. The principal (lower) coal bed is included in the Colorado 
formation and the upper one in the Fox Hills, the line between these two forma- 
tions being drawn in the second ridge above the lower coal bed. It should be 
remembered that the Colorado formation was then made to include the Fort Pierre 
division. 
Dr. White studied the section in 1877, and, after discussing the fossils collected in 
it, he states 7 that it is impracticable to refer the strata to any one or more of the 
established Cretaceous groups with certainty, but he thinks there is no reason to 
doubt that the greater part of the series at least is referable to the Fox Hills. 
Mr. Stanton spent several months studying the geology and paleon- 
tology of Coalville and vicinity, and observed many new and interest- 
ing facts. He carefully prepared a detailed section which shows the 
presence of about 6,000 feet of strata below the recognized Tertiary. 
Of this column about 1,700 feet are assigned to the Colorado, about 
2,800 feet to the Montana, and approximately 1,500 feet to the Lara- 
mie, or the nonfossiliferous strata which occupy the position that should 
be taken by the Laramie if it is present. 
None of the investigators previous to Mr. Stanton had noted the 
presence of fossil plants, but he, fortunately, found a rich deposit nearly 
1,000 feet above the base of the Montana, and overlain by fully 1,800 
feet of often richly fossiliferous marine Cretaceous, representing the 
upper portion of the Montana formation. The full details of his sec- 
tion and the lists of invertebrates may be found in his paper above 
cited. 8 There can, therefore, be absolutely no doubt as to their strati 
graphic position. 
The plants collected by Mr. Stanton were submitted to me for study, 
and a brief report on them is printed on page 42 of his bulletin. In 
that report I stated that the most important of the species " belong 
clearly to the Laramie group," and it should be remembered that this 
statement was in accord with the current conception of the Laramie 
when the Point of Rocks flora was regarded as typical. But, as 
1 Ann. Kept. TJ. S. Geol. and Geog. Surv. Terr., 1869, p. 91 (1870). 
2 Ibid., 1873, pp. 366, 371 (1874). 
3 lbid., 1870, pp. 168, 291. 
4 Ibid., 1872, p. 439 (1873). 
8 TJ. S. Geol. and Geog. Surv. Terr., Vol. IX, p.xxx; TJ. S. Geol. Expl. 40tb Parallel, Vol. IV, p. 11. 
6 U.S. Geol.Expl. 40th Parallel, Vol.1, pp. 316-319, 327-330 (1878); Vol. II, pp. 330-337 (1877). 
'Ann. Rept. U. S. Geol. and Geog. Surv. Terr., 1877, p. 239 (1879). 
8 Bull. TJ. S. Geol. Survey No. 106, pp 38-46. 
