54 FLORA OF THE MONTANA FORMATION. 
between them, the original specimen was sent to him, and his reply is 
as follows: 
( )n comparing your species with B. antiqua, there seems no characteristic differ- 
ence except in the venation. That, however, in your specimen is different not only 
in the fewer nerves, hut in their feebler and more tortuous development. It is 
jnst possible that yonr leaf may be a young depauperated or bleached leaf of B. 
antiqua; but if the others are like it in their characters this would not be likely. 
An examination of the material shows that the specimens all agree 
perfectly among themselves as to number and character of the nerves, 
and it is on this character alone that the species are separated. They 
are certainly very closely allied, and it is possible that more extensive 
material would show a variation sufficient to unite them. 
The differences may be briefly stated as follows : .A 7 . Dawsoni has 
eighteen rather strong nerves, while N~. intermedia has only twelve 
or thirteen relatively weak, tortuous nerves. Dawson has described, 
but not figured, another leaf under the name of Nelumbium saskatch- 
uense, 1 which is about the same size as those under discussion, but 
which has only seven nerves. 
The age of this last species is not stated positively, but it appears to 
belong to the Fort Union or the Upper Laramie of the Canadian geol- 
ogists. He has described still another species (N. pygmceum 2 ) from the 
Tertiary of the Similkameen River, British Columbia, which is not 
widely different. 
This genus appears to have been introduced in North America in the 
lower part of the Upper Cretaceous and to have continued until the 
present time. Following is a list of the North American species with 
the horizon of each : 
Nelumbium arcticum Heer, Atane beds, Greenland. 
Nelumbo Dawsoni Hollick, Belly River series. 
Nelumbo intermedia n. sp., Montana formation, Point of Rocks, Wyoming. 
Nelumbo laramiensis Hollick, Laramie formation, Florence, Colorado. 
Nelumbium tenuifolium Lx., Laramie formation, Sand Creek, Colorado. 
Nelumbium Lakesianum Lx., Denver group, Golden and Sedalia, Colorado. 
Nelumbium saskatchuense Dn., Canadian Upper Laramie?, Saskatchewan. 
Nelumbium pygrmeum Dn., Miocene, Similkameen River. 
Habitat. — Point of Rocks, Wyoming. Original Hayden collection, 
and also found by Lester F. Ward in 1882. 
Nelumbo? sp. 
PI. XIII, fig. 6. 
Castalia sp. Kn., Stanton and Knowlton, Bull. Geol. Soc. Am., Vol. VIII, p. 140" (1897). 
Leaf nearly circular in outline; peltate but not quite centrally so; ribs 
radiating, apparently numerous, and forking. 
The fragment figured is the only one of this form obtained. It appears 
1 Trans. Roy. Soc. Canada, Vol. V, Sec. IV, p. 35 (1887). 
2 Ibid., Vol. VIII, Sec. IV, p. 87, fig, 22 (1890). 
