FLORA OF THE KOOTAMF FORMA TIOX. 'M)\) 



not identify oi' iiainr, pi. i, fig. 4. The unnamed foi'ni, fig. 4, i.s .sti-ikingly 

 like some of the (leysei' plants and is ])i-ol)al)ly the same species. Z. 

 iiiniit(tna also is much like some of the forms from Montana, and the same 

 ma\' he .said of his Z. (((■iilij)C)n}is. Probably all are forms of Z. nrdicus. 

 It sliould he stated in this connection that in naming a Zamites from 

 the Great I'alls locality, Zann'lcs nionl(tn(ii.'<is, in my paper on "Some 

 Fossil Plants from the (ireat Falls of Montana," it had escaped m\- notice 

 that Dawson had previously named a Kootanic^ fossil Z. inotihuid. Tliese 

 names ai'(> loo much alike. Daw.son states that Z. )ntuil(inii has four 

 nerves, and he recognizes its closeness to Z. arciicus and to Z. brcviiK'tnns. 



It is ([uite possible that Z. borealin Heer and Z. aculipciinis are both 

 foi'ins of Z. (trrticus, differing from it only in the somewhat longer leaflets. 

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

 forms, Ptcroj)lii/llum Lyclliatium Dunk., Zann'tc.-^ montaiKi Dn., Z. horcdlis 

 Heer, and Z. acutipennis Heei', foi' whicdi 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 foi' which four nerves are given, to 

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

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

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

 antl Heer's Z. acuti))t'nnis, and he describes an additional form, which 

 he makes a new species, with the name Z. nperlus. This he says is a 

 small species resembling Z. ardicus, 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. ardicus, which it closely resembles. It is probable 

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



It is to Ik' 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 floi-as. 

 C3'cads of this type have not been found in the Lower Potomac strata 

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



" Am. .lonrn. Sri. for March, ISOl. 



