The Fort Union FornKition. — Weed. 201 
other plates have also been recovered, but they afford at pres- 
ent no additional knowledge regarding this or other species. 
1 have much pleasure in naming this species after the son 
of its discoverer, whose enthusiasm in the work promises 
greater results in the future, Dinichthijs prentis-clcu-kL 
THE FORT UNION FORMATION. 
By Walter Harvey Weed, Washington, D. C. 
The Fort Union group is a name familiar to all students of 
the Cretaceous formations of the Northwest. First used by 
Dr. F. V. Hayden, whose explorations of the upper Missouri 
form the basis of our present knowledge and classification of 
the Cretaceous of the great plains country, the name designa- 
ted the great lignite group of the "Country around Fort Union, 
extending northward into the British possessions to unknown 
distances; also southward to Fort Clark."* At the time the 
name was given the formation was also identified on the North 
Platte river above Fort Laramie, and on the west side of the 
Wind River mountains. Afterwards it was extended so as to 
include all the beds referred later to the Laramie (excepting 
the Judith River beds), as well as some still older formations. 
Abandoned by its sponsor for the later term Laramie, the 
name retained its place in geological literature owing to the 
earnest eli'orts of Dr. J. S. Newberry, who maintained that the 
beds to which the name was first applied constitute a totally 
distinct and independent formation of later age than the 
Laramie. I In his last paper upon this subject professor New- 
berry expressed his views quite clearly and forcibly, paying 
tribute to professor Ward's schokirly paper upon the flora of 
the Laramie group, which he claimed was really a description 
of the flora of the Fort Union formation. A later paper by 
KnowltonJ accepts this view. 
It seems unnecessary and out of place in this paper to dis- 
cuss the relations of the Laramie group, except to show tliat 
the Fort Union group does not belong to it. The recent dis- 
*Proc. Acad. Nat. Sci. Phila., vol. xiii, 1861, p. 433. 
"t"The Laramie Group. Trans. N. Y. Academy of Sciences, vol. ix, 
No. 1., Nov. 4, 1889. Also BuU. G. S. A., vol. i, p. 524. 
JFossil Plants from .the Fort Union prroup of Montana. Proc. U. S. 
National Museum, vol. xvi, p. 33, Washin<,'ton, 1893. 
