68 
Cycadophyta 
Zamites albertensis Berry n.sp. 
Plate XI, figures 1, 2 
Pinnules common, invariably detached from the rachis and usually 
more or less broken, ovate-lanceolate and falcate in outline, widest below 
the middle, tapering upward to the gradually narrowed inequilateral acute 
tip. Base broadly rounded. Texture coriaceous. Veins all alike and 
longitudinal, as far as observed simple and parallel, more or less immersed 
in the leaf substance, about 0*5 mms. apart. The material is carbonized, 
much compressed, and somewhat distorted and the complete venation is 
preserved only in the median and distal regions, so that it cannot be deter- 
mined if there was forking in the basal region, although this seems probable. 
No cuticular features can be made out. All of the pinnules seen are large, 
although there is some variation in width. Length between 17 and 20 
cms. Maximum width 3*6 cms. or sometimes as little as 3 cms. Veins 
identical throughout and hence 30 to 35 in number. 
This striking and rather interesting form is represented by numerous 
specimens. Associated with it on the same slabs are twigs of Geinitzia 
formosa and fragments of dicotyledonous leaves. I mention this to dispel 
any doubt that might arise regarding the horizon from which the specimens 
came, since such large cycadophyte pinnules are known from only con- 
siderably older Mesozoic horizons and material comparable in size to this 
Allison species is to be found chiefly in the Triassic rather than in the 
Cretaceous. In fact, except for a somewhat uncertain form from the 
Dakota sandstone and another from the Senonian (?) of Alaska, all of the 
North American records of Zamites are not younger than Lower Creta- 
ceous, although the genus is recorded from both the Cenomanian and 
Turonian of Europe, and there is no reason why the older Cretaceous forms 
should not form a continuous series with the similar remains that occur 
sparingly in the Tertiary of different parts of the world. 
The question of the identification and botanical relationships of 
Cycadophyte fronds and pinnules is a puzzling one, but I can see no reason 
for questioning the reference of the Allison material to the genus Zamites. 
Their inequilateral form points with what amounts almost to certainty 
to their pinnule character rather than to their representing some broad- 
leafed conifer like Dammara or some unknown type of monocotyledon with 
coriaceous leaves. 
The only forms of comparable size from beds anywhere near the age 
of the Allison formation are those described by Lesquereux from the 
Dakota sandstone under the name of Dammarites 1 , and these are not only 
less elongated, but relatively wider, more sparsely veined, more nearly 
equilateral, anti narrowed to the base. 
Another form that is possibly comparable, although it seems clearly 
to represent a totally different type of plant, is the leaves from the Ceno- 
manian of Bohemia referred by Velenovsky 2 to the genus Krannera, and 
of uncertain botanical affinity. 
1 Lesquereux, L.: Mon. U.S. Geel. Surv., vol. 17, p. 32, Pl. 1, figs. 9-11 (1892). 
1 Velenovsky, J.: Die Gymnoapermen der Bfihmiaehen Kreideformation, p. 1, PI. 1, figs. 1-7 (1885). 
