GEOLOGY AND PALEONTOLOGY. 129 
extensively developed in Dakota county, below the mouth of the Big Sioux river ; 
thence southward into northeastern Kansas and beyond.”’ 
In the discussion of the Dakota group they say: ‘‘Although we still retain 
this as a distinct rock, our present impression is that it is only a subdivision or 
member of the Fort Benton group. Still, until more fossils can be obtained from 
it in the region of typical localities, the question whether or not it should take 
rank as a distinct formation must remain anopen one. The position of the rock 
beneath the Benton indicates that it is certainly as old as that group, while the 
dicotyledonous leaves found in it prove that it cannot be older than the Cre- 
taceous.”’ 
In 1863 Professor Marcou, for the first time, visited the Dakota sandstone. 
He was accompanied by the Italian geologist, Capellini. Collections of leaves 
were made at Tekamah, Blackbird hill, and at the mouth of the Big Sioux river. 
Although up to this time Professor Marcou had contended for the Jurassic age 
of the beds, he was now convinced that they were Cretaceous. In an article 
published in 1864, ‘‘Une Reconnaissance Geologique au Nebraska,’’”’ this was 
frankly admitted. This practically ended the discussion, and settled one of the 
long-mooted questions of the geology of the West. 
LESQUEREUX’S WORK ON PALEOBOTANY. 
It was in 1866 that the descriptions of the leaves collected by Messrs. Marcou 
and Capellini were published, in a paper entitled ‘‘Les Phyllites Cr¢étacées du 
Nebraska.’’2> The account of the trip and description of localities were written 
by Professor Capellini, and the leaves were figured and described by Professor 
Heer. They include seventeen species, all of which are new. The article con- 
stitutes the first description of leaves from the Dakota; and from it nearly all 
the leaves since found in northeastern Nebraska have been identified. 
While the age of the Dakota in its type locality, near Sioux City and Black- 
bird hill, was practically settled by the admission of Professor Marcou, the age 
of what is now known to be the same rock in Kansas was much longer a matter 
of doubt. Prof. B. F. Mudge, in 1866, described the finding of a fossil footprint 
in the Liassic (?), on the Republican river, about fifty miles from its mouth, and 
stated that the Triassic, Jurassic and Cretaceous were all represented in that 
part of Kansas.2? Doctor Hayden, in speaking of the beds referred by Major 
Hawn to the Trias, says: ‘‘They may be Trias, Permian, or even Jurassic, as far 
as any evidence yet obtained goes. . . . We must await further evidence be- 
fore we can regard the existence of Trias in eastern Kansas as demonstrated.’ 
In 1869, however, Professor Mudge found marine invertebrates and dicotyledon- 
ous leaves in the same beds in Saline county, and referred the disputed forma- 
tion to the Dakota. 
Doctor Newberry published an article in 1868 describing the leaves collected 
by Meek and Hayden at various times and from various localities in the Dakota.*! 
It was intended that an extended report of the leaves follow this article, anda 
series of plates was prepared awaiting this report, which was to constitute vol- 
ume VIII of the Geological Survey of the Territories. The report, however, was 
never written, and in 1878 Doctor Hayden published a small edition of 500 copies 
of the plates.*” 
Leo Lesquereux, who afterward did more than any other man to further the 
27. Soc. Geol. France, Bull., 2e ser., 21: 132-146. 
28. Mem. de la Soc. Helvetique des Sci. Nat., 22, No. 1. 
29. Am. Jour. Sci., 41: 174-176. 30. Loc. cit., pp. 32-40. 
31. Annals Lyc. Nat. Hist. N. Y., 9: 1-76. 
32. Illust. of Cret. and Ter. Plants, Washington, 1878, 27 pl. 
ae 
