Series in Kansas, Oklahoma and New Mewico. 213 
Rhus Uddeni Lx.—The locality for this species is simply 
*‘Kansas.” It is said to have been presented to the U. S. 
National Museum by the collector, Prof. J. A. Udden, but accord- 
ing to the records it is not now and has never been in this institu- 
tion. I have lately written to Prof. Udden to find where it came 
from, and he replies that it is “from the west slope of the Smoky 
Hill Buttes, near Salemsburg Post Office, Saline county, Kansas.” 
Sterculia Snowit Lx.—From Ellsworth Co., Kansas, where it 
is very abundant. It was reported by Mr. W. F. Cummins from 
the “upper sandstone of the Tucumcari beds, four miles west of 
Big Tucumcari mountain, New Mexico,” and described by him 
under the name of Sterculia Draket. 3d Ann. Rep. Geol. Survey 
of Texas, p. 210. 
Sassafras Mudgei Ux. —Found on hills along the Salina river, 
Kansas. 
Sassafras cretaceum var. obtusum Lx.—Also found on bluffs 
along the Salina valley, Kansas. 
Sassafras n. sp.—This is a small leaf differing from any hereto- 
fore described. It, however, approaches to certain well known 
forms from Kansas. 
Glyptostrobus gracillinus Lx.—Found near Sioux City, Iowa, 
at the mouth of Iowa creek. The collection from near Belvidere 
contains a number of fairly well preserved examples and there can 
be no question of its correct identification. 
Sequoia ? sp.—The collection contains a number of fragmentary 
cones which appear to belong to this genus. I have not been 
able to identify them with any known species, and they may be 
new, although it is hardly safe to found species on such imperfect 
material. 
Indeterminable dicotyledons.—Besides the forms enumerated 
above, there are a number of fragmentary leaves that it is impossi- 
ble to determine with satisfaction. They are undoubtedly dicoty- 
ledons, but are only fragments with hardly a trace of nervation 
preserved. 
All the above mentioned species belong to the Dakota group 
as it is usually accepted, but as a matter of fact no detailed strati- 
graphic work has yet been done with a view to ascertaining the 
range and association of the fossil plants referred to this forma- 
tion. It would be natural to suppose that a formation of great 
thickness and wide areal extent, would have horizons capable of 
differentiation by means of the ‘fossil plants, but they have not 
yet been worked out. 
If it is shown by stratigraphic and paleontologic data that these 
leaves come from a horizon lower than that usually recognized 
as the Dakota group, it would be quite in accord with what should 
be expected of the Dakota flora. This flora, for years supposed 
to be the oldest of its type in North America, is made up of a 
great number of highly differentiated forms, that must have had 
an anterior period of development. That is, the flora could not 
have sprung into existence in so abrupt a manner as would seem 
