39 
age, since the forked laterals upon which its positive determination depends 
are not visible in all specimens, although they can usually be seen if searched 
for. With this in mind this species should prove one of the most valuable 
horizon markers for the field geologist. 
The present is the smallest known species of Oleandra, either living or 
fossil, and it is difficult to picture its reaching such a profuse development 
if it had to compete for space on the ground with the large ferns and other 
elements of the Kootenay flora, and this leads to the suggestion that it 
may well have been pendant as a Kootenay epiphyte. 
Occurrence. Localities CK1, CK2, CM1, CN1, CN2, COl, CQ3, CQ4, 
DG1, and DH1. 
Genus, cladophlebis Brongniart 
Cladophlebis heterophylla Fontaine 
Plate Y, figures 1-4 
Cladophlebis heterophylla Fontaine, TJ.S. Nat. Mas. Proc., vol. 15, p. 493, 
PL 84, fig. 2 (1892) ; in Ward, TJ.S. Geol. Surv., Mon. 48, p. 294, 
Pl. 71, figs. 21-25 (1906). 
Pecopteris borealis Fontaine (non Brongniart), in Ward, 19th Ann. Kept., 
U.S. Geol. Surv., pt. 2, p. 655, PL 160, figs. 14, 15 (1899). 
Heer, Flora Fossilis Arctica, Bd. 1, p. 81, PL 1, fig. 14; PL 44, figs. 5a, 
b (1868) (not Atane identification of 1880). 
This well-marked species with tiny rounded or triangular pinnules is 
a prominent and characteristic element in the Kootenay, and one of the 
best types for field recognition in its flora. It is quite variable in details, 
but its long, slender pinnae with small, rounded pinnules give it a facies 
readily recognizable. The accompanying figures show its general char- 
acter and the limits of variation in size and venation. 
It is not especially close to other described species of Cladophlebis, 
but does resemble a number of Lower Cretaceous forms that go by other 
names. For example, it is much like what Seward wrongly called Nathorstia 
valdensis from the English Wealden, and what Schenk (not Dunker or 
Gutbier) called Pecopteris geiniizi from the German Wealden. It also 
resembles Dichopteris delicatula Seward of the English Wealden, in which, 
however, the venation is unknown. Single pinnae are suggestive of some 
fossil species of Gleichenia, as for example Gleichenia longipennis , rotula f 
and delicatula , but the habit is, of course, markedly different. 
The species occurs in the Knoxville beds of California and in the 
Cloverly, the supposed equivalent of the Kootenay in Wyoming, in the 
Fuson formation of eastern Wyoming, and probably in the Kome beds of 
western Greenland. 
Occurrence . Localities CK1, COl, DG1, and DH1. 
Cladophlebis montanense (Fontaine) Berry 
Aspidium montanense Fontaine, U.S. Nat. Mus. Proc., vol. 15, p. 490, 
PL 82, figs. 1-3; PL 83, figs. 2, 3 (1892). 
Aspidium monocarpum Fontaine, Idem., Pl. 83, figs. 4-6; Pl. 84, fig. 3. 
