FLORA OF THE KOOTAMK FOU.MATION. 307 



from Zdinilcs airtidiH (liipp. Ilcci' (lescrilx's from llio Kome ho'ds of 

 Clreeiilaiul," a numljer of specimens of this plant, and ffom the same beds 

 a smallei' form which he calls Z. hrcvi/icniiis.'' The latter, except in size, 

 seems to he iflentical with Z. arcticus imd has many features found in the 

 Cieyser {)lanl. lnde(>d, the latter seems to give coiuuM'ting links between 

 the two, which make them difficult to separate. The ( ieysei' specimens 

 ai'e preserved on a fine-grained shal(\ which gi\('s d(>tails not to be seen 

 on a coarser grained rock. This plant and Xil.'«)i/i<i scliauinhutycnsis 

 are much the most common fossils in the (ieyser sti'ata, and they are 

 the plants most characteristic of them. Heer gives no nerves foi- Zatnitcs 

 aniiciis and Z. hren'poniis. The only diffei'ence that 1 can find between 

 them and the (ieyser plant is the greatei- size of the U^aflets on s()m(> of 

 the leaves of the latter, a point wliich in such cycads is of little im]X)rtance. 

 Besides, in the numerous Geyser specimens forms can l)e found which 

 are similar in size to both Z. ardicuK and Z. brcvlpcitnix. The descrip- 

 tion that Heer gives of these plants agrees closely with the chai-actei's 

 seen in the Geyser plant. Heer himself, in his description of Z. linri/icn- 

 nis, gives as the only difference l:)etween it and Z. aniicu.s the smaller 

 size of the leaves of the former and its shorter leaflets. 



The number of imprints found in the Geyser beds and their good 

 preservation enable me to add something to the descriptions given by 

 Heer. There is some variability in the Geyser forms, some having wider 

 leaflets and some narrower. Some of the leaflets from the same portion 

 of the leaf are decidedly smaller than others, and the length of the leaflets 

 from the middle portion of the leaves is shorter in some specimens than 

 in others. But there are intermediate sizes that show that all l)elong 

 to the same plant. Only fragments of leaves arc seen, but some of these 

 are 7 cm. long, showing that some at least attained considerable size, 

 for these portions are from the middle part of the leaf and it does not 

 change in width throughout the entire length. The midrib is broad and 

 flat, being mostly hidden by the bases of the leaflets, which are attached 

 upon its upper face. The leaflets diminish in length toward the base 

 of the leaf, which indicates that, as is usual in cycadean leaves, they 

 are supported in this case also by naked petioles. The opposite leaflets 



" Flor. Fos.s. .\rct., Vol. I, p. 82, pi. iii, fig. 1-1 [this is ji cupy of (luppeilV lig. 9, see synonyiny nliove); 

 pi. xliv, fig. 5o. Ibid., Vol. Ill, Pt. II (Kreidc-FIora dcr Arctisclien Zone), p. 07, pi. .\v, figs. G, 7. 

 b Ibid., Vol. Ill, p. G7, pi. XV, figs. S, <), 10. 



