128 KANSAS ACADEMY OF SCIENCE. 
ing the paleobotanica! evidence of the age of the Dakota began. It will be re- 
membered that Meek and Hayden had sent drawings of some of the leaves from 
this group to Professor Heer, who expressed an opinion that they belonged to the 
Tertiary. Doctor Newberry, however, to whom the leaves themselves had been 
submitted, considered them Cretaceous. Ina letter to Prof. J. D. Dana, pub- 
lished in the American Journal of Science, Doctor Lesquereux quotes from 
Professor Heer, among other things, the following sentences: 
‘*Your views of the flora of North America agree perfectly with what we find 
in Europe. This leads me to believe that the plants of Nebraska belong to the 
Tertiary and not to the Cretaceous formation. It is true that I have seen only 
some drawings which were sent to me by Messrs. Hayden and Meek, but they are 
all Tertiary types. The supposed Crednaria is very like Populus luce Ung. of 
the Lower Miocene; and the Hitinghaus:ana seems hardly rightly determined. 
Besides, it is a genus badly founded, and has as yet no value. All the other 
plants mentioned by Doctor Newberry belong to genera that are represented in 
the Tertiary and not in the Cretaceous. It is very improbable that in America 
the Cretaceous flora has had the characteristic plants of the Tertiary, and this 
would be the case if these plants did belong to the Cretaceous.’’*! 
Doctor Newberry took exception to these statements, and replied at length in 
a letter dated October 15, 1859, likewise published in the American Journal of 
Science.*> He answered the objections of the Swiss professor in detail, and 
made the statement, which has since been universally accepted, that the vegeta- 
tion in Cretaceous times had the same general aspect as that of the present. 
Professor Lesquereux replied to this letter with another, in which he defended 
Professor Heer’s statements, and discussed at some length the position of both 
parties.» Doctor Newberry again replied, reiterating his former statements, and 
answering the criticisms of Professor Lesquereux.** And finally Professor Heer, 
in an article published in May, 1861, defended his position, namely, that the 
plants are Tertiary rather than Cretaceous, if judged from the standpoint of 
European paleobotany.”» This discussion added little to the settlement of the 
point at issue, and was at the time regretted by the gentlemen engaged in the 
controversy. Both Professors Heer and Lesquereux afterward came to accept the 
position of Doctor Newberry. 
Meek and Hayden, in 1861, published a paper in which they in a general way 
discuss the geology of the entire upper Missouri region. In this paper they 
finally complete the section of the Cretaceous rocks first published in 1853, and 
which from time to time had been revised and elaborated. As completed, the 
section includes 2600 feet of strata, and is divided into the following groups, cor- 
responding to the numbers formerly employed :*° 
No. \5.-- Fox Hills beds: ..4.iacsccadeee ole uke oo nkte cue 500 feet. 
No, 4.) Bert Pierre groups, i, cocoa ates seis psd ineie sels 700, :** 
No..d. , Niahrara: prong, |... Acc ueaseeine oe le nd= a0 nae 200 ‘S 
No; 2: ‘Fort Bente prowe.:. .:cenemen iene s = 44s )c fe gene se 800 ‘ 
No, i: Dakotas pagp s0.55 15. Sa et ae Mev de lo Secs cote 400 * 
The description of the Dakota group, which for the first time bears that name, 
and in which we are particularly interested, is as follows: ‘‘ Yellowish, reddish 
and occasionally white sandstone, with, at places, alternations of variously colored 
clays and beds and seams of impure lignite. Also silicified wood and great num- 
bers of leaves of the higher types of dicotyledons; with casts of Pharella? 
dakotensis, Axinella siouxensis, and Cyprina arenaria.”’ 
The description of the locality is: ‘‘ Hills back of the town of Dakota; also 
21. Am. Jour. Sci., 28: 85-89, 22. Loc. cit., 29: 208-218, 
23. Ibid., 434-436. 24. Loc. cit., 30: 273-275. 
25. Loc. cit., 31: 435-440. 26. Proc. Phila. Acad. Sci., 1862, p. 419. 
