FLORA OF THE KOOTANIE FORMATION. 309 



not identify or name, pi. i, fig. 4. The unnamed form, fig. 4, is strikingly 

 like some of the Geyser plants and is probably the same species. Z. 

 montana also is much like some of the forms from Montana, and the same 

 ma}^ be said of his Z. acutipennis. Probably all are forms of Z. arcticus. 

 It should be stated in this connection that in naming a Zamites from 

 the Great Falls locality, Zamites montanensis, in my paper on "Some 

 Fossil Plants from the Great Falls of Montana," it had escaped my notice 

 that Dawson had previously named a Kootanie fossil Z. montana. These 

 names are too much alike. Dawson states that Z. montana has four 

 nerves, and he recognizes its closeness to Z. arcticus and to Z. brevipennis. 



It is quite possible that Z. horealis Heer and Z. acutipennis are both 

 forms of Z. arcticus, differing from it only in the somewhat longer leaflets. 

 Heer gives four nerves for each of these. In all these Lower Cretaceous 

 forms, Pterophyllum Lyellianurii Dunk., Zamites montana Dn., Z. horealis 

 Heer, and Z. acutipennis Heer, for which four nerves are given, the 

 nerves are slender and immersed in the thick parenchyma of the leaflets ; 

 hence it is quite possible that they may have had more than four. From 

 wrinkling in thick leaves of this type, owing to shrinkage along certain 

 nerves, deceptive appearances are often given in the nervation. As it 

 does not appear from the descriptions how distinctly nerves were seen 

 in these plants, I hesitate, for those for which four nerves are given, to 

 maintain their identity with Z. arcticus. Dr. J. S. Newberry, in an 

 article describing some plants from the Great Falls coal fleld of Mon- 

 tana," states that he recognized in these fossils Dawson's Z. montana 

 and Heer's Z. acutipennis, and he describes an additional form, which 

 he makes a new species, with the name Z. apertus. This he saj^s is a 

 small species resembling Z. arcticus, but is much more open in structure. 

 The nerves are invisible, according to his statement. The figure (fig. 4) 

 which Newberry gives of this plant does not show leaflets more distinct 

 than those of Z. arcticus, which it closely resembles. It is probable 

 that all of these forms are those of Z. arcticus. 



It is to be noted that this type of cycad seems to be quite char- 

 acteristic of the Kootanie beds of Canada and of the strata of similar 

 age in Montana, forming a connecting link between the two floras. 

 Cycads of this type have not been found in the Lower Potomac strata 

 of Virginia, which have so many other forms that occur in the Mon- 



<* Am. Journ. Sci. for March, 1891. 



