66 
THE ALLISON FLORA 
By Edward W. Berry, Johns Hopkins University 
Page 
129, 131 
Illustrations 
Plates XI-XIL Illustrations of fossils 
The fossil plants from the lower part of the Allison formation from 
east of Crowsnest lake, Blairmore district, western Alberta, comprise 
representatives of about a dozen species, of which it has been possible to 
identify eight with more or less certainty. 
The coarseness of the matrix and more specially the deformation of 
the beds have either not preserved or have partly obliterated certain 
essential features of the contained plants, thus causing some of the identi- 
fications to be less certain than is desirable. 
It has been possible to correlate all of the named plants from the 
Allison formation with previously described species from other areas except 
the large and, in some ways remarkable, new species of Zamites. 
The flora of this part of the Upper Cretaceous is very imperfectly 
known either in North America or Europe. This is due in part to the 
prevailingly marine character of many of the outcrops, in part to lack of 
collections, and to the fragmentary nature of many of the fossils collected. 
In western Canada a considerable flora has been described from the 
Upper Cretaceous rocks of Vancouver island, by Dawson, This has 
nothing in common with the plants from the Allison formation, which 
appear to represent an earlier horizon. The same author described a small 
flora from the Belly River formation, but this also appears to have nothing 
in common with the Allison flora, possibly because of the incomplete char- 
acter of both. 
In the United States small florules have been recorded from the Eagle 
sandstone and Judith River formations of Montana, from the Trinidad 
sandstone of Colorado and New Mexico, from the Kirtland formation of 
New Mexico, the Adaville formation of Wyoming, and the Fox Hills 
formation of Colorado; and somewhat more extensive floras are known 
from the Mesa verde formation of Wyoming and the Vermejo formation of 
Colorado and New Mexico. 
All of these are referred to the Montana group and although they are 
too incomplete to furnish. a precise chronology of Upper Cretaceous palseo- 
botany, they are much more representative than the few plants known from 
the Colorado group and represented by those recorded from the Frontier 
formation of Wyoming and the Mill Creek formation of British Columbia. 
Regarding the bearing of the present flora on the age of the Allison 
formation it may be said that the smallness of the collection and the 
incomplete state of our knowledge of the floras from comparable horizons, 
emphasized in a foregoing paragraph, render it impossible to draw precise 
conclusions. 
The Allison flora is clearly younger than the known floras mentioned 
above from the Colorado group, and it is just as conclusively older than 
