162 KANSAS ACADEMY OF SCIENCE. 
In regard to the geographical distribution of the flora, it has already been 
stated that the leaves have been found in every locality that contains Dakota 
outcrops, and at almost every exposure. They have been collected west of Bel- 
videre, in Clark county; on Bear creek, in the extreme western part of the state; 
and along the Arkansas river, at Great Bend, Pawnee Rock, and Larned. The 
region which has yielded not only a greater variety of forms but also a greater 
number of specimens than any other is also the region in which the Dakota 
reaches its best development, viz., eastern Ellsworth county, Kansas. This is 
the famous collecting ground of Mudge, Snow, West, and Sternberg. Leaves 
are found on Bluff, Thompson, and Oxide creeks, south of the Smoky Hill river; 
and on the north side, near the towns of Kanopolis, Ellsworth, Carneiro, and 
Terra Cotta, they may be collected on every hill. Near Brookville and Tescott 
there are prolific localities, as also in the vicinity of Minneapolis and Glasco. 
One of the finest collecting grounds known is at Bond’s mill, in Washington 
county, Kansas. From this point leaves are found as far northwest as Fair- 
bury, Neb. Doctor Lesquereux reports leaves from Beatrice. The outcrops of 
Dakota near Lincoln furnish a few rather poor specimens. Along the Platte 
river some fairly good leaves have been found. The bluffs of the Missouri from: 
Omaha to Sioux City yield some good leaves, especially points near Tekamah, 
Golden spring, Decatur, and Blackbird hill, Neb., and Sergeant’s bluff, lowa. 
It may not be ill advised to mention in this connection the increase in the 
number of known species from time to time. Professor Heer, in his ‘‘ Phyllites 
Crétac¢ées du Nebraska,’ discusses seventeen species; in Doctor Lesquereux’s 
first paper, in 1868, fifty-three new forms were mentioned: while in 1874, at the 
time of the publication of his ‘‘ Cretaceous Flora,’’ the number had been increased 
to 130. In his ‘‘ Cretaceous and Tertiary Flora,’’ in 1883, 190 species are mentioned. 
The discovery of the magnificent leaf beds in Ellsworth county so increased the 
number of forms that, when Doctor Lesquereux began his ‘‘ Flora of the Dakota 
Group,’’ in 1885, 350 species were known; and the addition of 110 forms from the 
collections of Sternberg brought the number up to 460. Of these, six are ferns, 
twelve cycads, fifteen conifers, and 429 dicotyledons. The latter class forms over 
ninety per cent. of the entire series. Since the appearance of ‘‘The Flora of the 
Dakota Group”’ comparatively little work has been done on the paleontology of 
the Dakota. Hollick, Ward, and others have described a few new leaves, prob- 
ably less than a score of species in all. The collections made in Kansas in 1897 
and 1898 by Dr. Lester F. Ward and the writer, and in Nebraska, by the writer, 
in 1899, have yielded a number of new forms, the greater part of which are now 
in the museum of the University of Nebraska. (See plate XII.) 
In the discussion of the stratigraphy of the group it has been shown that 
there is no continuity of strata in the Dakota. Sandstones and shales are strati- 
fied indiscriminately with clays throughout the formation. This of itself points 
to changing conditions of sedimentation. It was this marked peculiarity, as well © 
as the manner in which the leaves were deposited, that led Doctor Lesquereux to 
adopt his views of the manner of deposition of the Dakota, which are now almost 
universally accepted among students of the group. It is unnecessary to reiterate 
the statement that, in the main, the opinions of the writer coincide with those 
of Doctor Lesquereux. For this reason (and even at the risk of being thought to 
quote too fully), the following paragraphs from this noted author are herewith 
given. They represent his latest thought, having been written after he had 
worked over the last collection of Sternberg, shortly before his death: 
‘*In my ‘Cretaceous Flora’ the question concerning the probable derivation of 
the numerous vegetable remains found in the shaly sandstone of the Dakota 
